Machine learning for identifying Randomized Controlled Trials: An evaluation and practitioner's guide

Palivizumab for preventing severe respiratory syncytial virus (RSV) infection in children

BACKGROUND

Respiratory viruses are the leading cause of lower respiratory tract infection (LRTI) and hospitalisation in infants and young children. Respiratory syncytial virus (RSV) is the main infectious agent in this population. Palivizumab is administered intramuscularly every month during five months in the first RSV season to prevent serious RSV LRTI in children. Given its high cost, it is essential to know if palivizumab continues to be effective in preventing severe RSV disease in children.

OBJECTIVES

To assess the effects of palivizumab for preventing severe RSV infection in children.

SEARCH METHODS

We searched CENTRAL, MEDLINE, three other databases and two trials registers to 14 October 2021, together with reference checking, citation searching and contact with study authors to identify additional studies. We searched Embase to October 2020, as we did not have access to this database for 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), including cluster-RCTs, comparing palivizumab given at a dose of 15 mg/kg once a month (maximum five doses) with placebo, no intervention or standard care in children 0 to 24 months of age from both genders, regardless of RSV infection history.  DATA COLLECTION AND ANALYSIS: We used Cochrane's Screen4Me workflow to help assess the search results. Two review authors screened studies for selection, assessed risk of bias and extracted data. We used standard Cochrane methods. We used GRADE to assess the certainty of the evidence. The primary outcomes were hospitalisation due to RSV infection, all-cause mortality and adverse events. Secondary outcomes were hospitalisation due to respiratory-related illness, length of hospital stay, RSV infection, number of wheezing days, days of supplemental oxygen, intensive care unit length of stay and mechanical ventilation days.

MAIN RESULTS

We included five studies with  a total of 3343 participants. All studies were parallel RCTs, assessing the effects of 15 mg/kg of palivizumab every month up to five months compared to placebo or no intervention in an outpatient setting, although one study also included hospitalised infants. Most of the included studies were conducted in children with a high risk of RSV infection due to comorbidities like bronchopulmonary dysplasia and congenital heart disease. The risk of bias of outcomes across all studies was similar and predominately low.  Palivizumab reduces hospitalisation due to RSV infection at two years' follow-up (risk ratio (RR) 0.44, 95% confidence interval (CI) 0.30 to 0.64; 5 studies, 3343 participants; high certainty evidence). Based on 98 hospitalisations per 1000 participants in the placebo group, this corresponds to 43 (29 to 62) per 1000 participants in the palivizumab group. Palivizumab probably results in little to no difference in mortality at two years' follow-up (RR 0.69, 95% CI 0.42 to 1.15; 5 studies, 3343 participants; moderate certainty evidence). Based on 23 deaths per 1000 participants in the placebo group, this corresponds to 16 (10 to 27) per 1000 participants in the palivizumab group. Palivizumab probably results in little to no difference in adverse events at 150 days' follow-up (RR 1.09, 95% CI 0.85 to 1.39; 3 studies, 2831 participants; moderate certainty evidence). Based on 84 cases per 1000 participants in the placebo group, this corresponds to 91 (71 to 117) per 1000 participants in the palivizumab group. Palivizumab probably results in a slight reduction in hospitalisation due to respiratory-related illness at two years' follow-up (RR 0.78, 95% CI 0.62 to 0.97; 5 studies, 3343 participants; moderate certainty evidence). Palivizumab may result in a large reduction in RSV infection at two years' follow-up (RR 0.33, 95% CI 0.20 to 0.55; 3 studies, 554 participants; low certainty evidence). Based on 195 cases of RSV infection per 1000 participants in the placebo group, this corresponds to 64 (39 to 107) per 1000 participants in the palivizumab group. Palivizumab also reduces the number of wheezing days at one year's follow-up (RR 0.39, 95% CI 0.35 to 0.44; 1 study, 429 participants; high certainty evidence).

AUTHORS' CONCLUSIONS

The available evidence suggests that prophylaxis with palivizumab reduces hospitalisation due to RSV infection and results in little to no difference in mortality or adverse events. Moreover, palivizumab results in a slight reduction in hospitalisation due to respiratory-related illness and may result in a large reduction in RSV infections. Palivizumab also reduces the number of wheezing days. These results may be applicable to children with a high risk of RSV infection due to comorbidities. Further research is needed to establish the effect of palivizumab on children with other comorbidities known as risk factors for severe RSV disease (e.g. immune deficiencies) and other social determinants of the disease, including children living in low- and middle-income countries, tropical regions, children lacking breastfeeding, living in poverty, or members of families in overcrowded situations.

Applying machine classifiers to update searches: Analysis from two case studies

Manual screening of citation records could be reduced by using machine classifiers to remove records of very low relevance. This seems particularly feasible for update searches, where a machine classifier can be trained from past screening decisions. However, feasibility is unclear for broad topics. We evaluate the performance and implementation of machine classifiers for update searches of public health research using two case studies. The first study evaluates the impact of using different sets of training data on classifier performance, comparing recall and screening reduction with a manual screening ‘gold standard’. The second study uses screening decisions from a review to train a classifier that is applied to rank the update search results. A stopping threshold was applied in the absence of a gold standard. Time spent screening titles and abstracts of different relevancy‐ranked records was measured. Results: Study one: Classifier performance varies according to the training data used; all custom‐built classifiers had a recall above 93% at the same threshold, achieving screening reductions between 41% and 74%. Study two: applying a classifier provided a solution for tackling a large volume of search results from the update search, and screening volume was reduced by 61%. A tentative estimate indicates over 25 h screening time was saved. In conclusion, custom‐built machine classifiers are feasible for reducing screening workload from update searches across a range of public health interventions, with some limitation on recall. Key considerations include selecting a training dataset, agreeing stopping thresholds and processes to ensure smooth workflows.

Clinical trials in COVID-19 management & prevention: A meta-epidemiological study examining methodological quality

OBJECTIVE

To describe the characteristics of Covid-19 randomized clinical trials (RCTs) and examine the association between trial characteristics and the likelihood of finding a significant effect.

STUDY DESIGN

We conducted a systematic review to identify RCTs (up to October 21, 2020) evaluating drugs or blood products to treat or prevent Covid-19. We extracted trial characteristics (number of centers, funding sources, and sample size) and assessed risk of bias (RoB) using the Cochrane RoB 2.0 tool. We performed logistic regressions to evaluate the association between RoB due to randomization, single vs. multicentre, funding source, and sample size, and finding a statistically significant effect.

RESULTS

We included 91 RCTs (n = 46,802); 40 (44%) were single-center, 23 (25.3%) enrolled <50 patients, 28 (30.8%) received industry funding, and 75 (82.4%) had high or probably high RoB. Thirty-eight trials (41.8%) reported a statistically significant effect. RoB due to randomization and being a single-center trial were associated with increased odds of finding a statistically significant effect.

CONCLUSIONS

There is high variability in RoB among Covid-19 trials. Researchers, funders, and knowledge-users should be cognizant of the impact of RoB due to randomization and single-center trial status in designing, evaluating, and interpreting the results of RCTs.

REGISTRATION

CRD42020192095.

Avoidance of bottles during the establishment of breastfeeds in preterm infants

BACKGROUND

Preterm infants often start milk feeds by gavage tube. As they mature, sucking feeds are gradually introduced. Women with preterm infants may not always be in hospital to breastfeed their baby and need an alternative approach to feeding. Most commonly, milk (expressed breast milk or formula) is given by bottle. Whether using bottles during establishment of breastfeeds is detrimental to breastfeeding success is a topic of ongoing debate.

OBJECTIVES

To identify the effects of avoidance of bottle feeds during establishment of breastfeeding on the likelihood of successful breastfeeding, and to assess the safety of alternatives to bottle feeds.

SEARCH METHODS

A new search strategy was developed for this update. Searches were conducted without date or language limits in September 2021 in: MEDLINE, CENTRAL, and CINAHL.  We also searched the ISRCTN trial registry and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.  SELECTION CRITERIA: We included RCTs and quasi-RCTs comparing avoidance of bottles with use of bottles for preterm infants where their mothers planned to breastfeed.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. When appropriate, we contacted study authors for additional information. We used the GRADE approach to assess the certainty of evidence. Outcomes included full breastfeeding and any breastfeeding on discharge home and at three and six months after discharge, as well as length of hospital stay and episodes of infant infection. We synthesised data using risk ratios (RR), risk differences (RD) and mean differences (MD), with 95% confidence intervals (CI). We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included seven trials with 1152 preterm infants in this updated review. There are three studies awaiting classification. Five included studies used a cup feeding strategy, one used a tube feeding strategy and one used a novel teat when supplements to breastfeeds were needed. We included the novel teat study in this review as the teat was designed to closely mimic the sucking action of breastfeeding. The trials were of small to moderate size, and two had high risk of attrition bias. Adherence with cup feeding was poor in one of the studies, indicating dissatisfaction with this method by staff or parents (or both); the remaining four cup feeding studies provided no such reports of dissatisfaction or low adherence. Avoiding bottles may increase the extent of full breastfeeding on discharge home (RR 1.47, 95% CI 1.19 to 1.80; 6 studies, 1074 infants; low-certainty evidence), and probably increases any breastfeeding (full and partial combined) on discharge (RR 1.11, 95% CI 1.06 to 1.16; studies, 1138 infants; moderate-certainty evidence). Avoiding bottles probably increases the occurrence of full breastfeeding three months after discharge (RR 1.56, 95% CI 1.37 to 1.78; 4 studies, 986 infants; moderate-certainty evidence), and may also increase full breastfeeding six months after discharge (RR 1.64, 95% CI 1.14 to 2.36; 3 studies, 887 infants; low-certainty evidence). Avoiding bottles may increase the occurrence of any breastfeeding (full and partial combined) three months after discharge (RR 1.31, 95% CI 1.01 to 1.71; 5 studies, 1063 infants; low-certainty evidence), and six months after discharge (RR 1.25, 95% CI 1.10 to 1.41; 3 studies, 886 infants; low-certainty evidence). The effects on breastfeeding outcomes were evident at all time points for the tube alone strategy and for all except any breastfeeding three months after discharge for cup feeding, but were not present for the novel teat. There were no other benefits or harms including for length of hospital stay (MD 2.25 days, 95% CI -3.36 to 7.86; 4 studies, 1004 infants; low-certainty evidence) or episodes of infection per infant (RR 0.70, 95% CI 0.35 to 1.42; 3 studies, 500 infants; low-certainty evidence).

AUTHORS' CONCLUSIONS

Avoiding the use of bottles when preterm infants need supplementary feeds probably increases the extent of any breastfeeding at discharge, and may improve any and full breastfeeding (exclusive) up to six months postdischarge. Most of the evidence demonstrating benefit was for cup feeding. Only one study used a tube feeding strategy. We are uncertain whether a tube alone approach to supplementing breastfeeds improves breastfeeding outcomes; further studies of high certainty are needed to determine this.

Antibody and cellular therapies for treatment of covid-19: a living systematic review and network meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of antiviral antibody therapies and blood products for the treatment of novel coronavirus disease 2019 (covid-19).

DESIGN

Living systematic review and network meta-analysis, with pairwise meta-analysis for outcomes with insufficient data.

DATA SOURCES

WHO covid-19 database, a comprehensive multilingual source of global covid-19 literature, and six Chinese databases (up to 21 July 2021).

STUDY SELECTION

Trials randomising people with suspected, probable, or confirmed covid-19 to antiviral antibody therapies, blood products, or standard care or placebo. Paired reviewers determined eligibility of trials independently and in duplicate.

METHODS

After duplicate data abstraction, we performed random effects bayesian meta-analysis, including network meta-analysis for outcomes with sufficient data. We assessed risk of bias using a modification of the Cochrane risk of bias 2.0 tool. The certainty of the evidence was assessed using the grading of recommendations assessment, development, and evaluation (GRADE) approach. We meta-analysed interventions with ≥100 patients randomised or ≥20 events per treatment arm.

RESULTS

As of 21 July 2021, we identified 47 trials evaluating convalescent plasma (21 trials), intravenous immunoglobulin (IVIg) (5 trials), umbilical cord mesenchymal stem cells (5 trials), bamlanivimab (4 trials), casirivimab-imdevimab (4 trials), bamlanivimab-etesevimab (2 trials), control plasma (2 trials), peripheral blood non-haematopoietic enriched stem cells (2 trials), sotrovimab (1 trial), anti-SARS-CoV-2 IVIg (1 trial), therapeutic plasma exchange (1 trial), XAV-19 polyclonal antibody (1 trial), CT-P59 monoclonal antibody (1 trial) and INM005 polyclonal antibody (1 trial) for the treatment of covid-19. Patients with non-severe disease randomised to antiviral monoclonal antibodies had lower risk of hospitalisation than those who received placebo: casirivimab-imdevimab (odds ratio (OR) 0.29 (95% CI 0.17 to 0.47); risk difference (RD) -4.2%; moderate certainty), bamlanivimab (OR 0.24 (0.06 to 0.86); RD -4.1%; low certainty), bamlanivimab-etesevimab (OR 0.31 (0.11 to 0.81); RD -3.8%; low certainty), and sotrovimab (OR 0.17 (0.04 to 0.57); RD -4.8%; low certainty). They did not have an important impact on any other outcome. There was no notable difference between monoclonal antibodies. No other intervention had any meaningful effect on any outcome in patients with non-severe covid-19. No intervention, including antiviral antibodies, had an important impact on any outcome in patients with severe or critical covid-19, except casirivimab-imdevimab, which may reduce mortality in patients who are seronegative.

CONCLUSION

In patients with non-severe covid-19, casirivimab-imdevimab probably reduces hospitalisation; bamlanivimab-etesevimab, bamlanivimab, and sotrovimab may reduce hospitalisation. Convalescent plasma, IVIg, and other antibody and cellular interventions may not confer any meaningful benefit.

SYSTEMATIC REVIEW REGISTRATION

This review was not registered. The protocol established a priori is included as a data supplement.

FUNDING

This study was supported by the Canadian Institutes of Health Research (grant CIHR- IRSC:0579001321).

READERS' NOTE

This article is a living systematic review that will be updated to reflect emerging evidence. Interim updates and additional study data will be posted on our website (www.covid19lnma.com).

Machine Learning Approaches to Retrieve High-Quality, Clinically Relevant Evidence From the Biomedical Literature: Systematic Review

BACKGROUND

The rapid growth of the biomedical literature makes identifying strong evidence a time-consuming task. Applying machine learning to the process could be a viable solution that limits effort while maintaining accuracy.

OBJECTIVE

The goal of the research was to summarize the nature and comparative performance of machine learning approaches that have been applied to retrieve high-quality evidence for clinical consideration from the biomedical literature.

METHODS

We conducted a systematic review of studies that applied machine learning techniques to identify high-quality clinical articles in the biomedical literature. Multiple databases were searched to July 2020. Extracted data focused on the applied machine learning model, steps in the development of the models, and model performance.

RESULTS

From 3918 retrieved studies, 10 met our inclusion criteria. All followed a supervised machine learning approach and applied, from a limited range of options, a high-quality standard for the training of their model. The results show that machine learning can achieve a sensitivity of 95% while maintaining a high precision of 86%.

CONCLUSIONS

Machine learning approaches perform well in retrieving high-quality clinical studies. Performance may improve by applying more sophisticated approaches such as active learning and unsupervised machine learning approaches.

Interventions to improve adherence to pharmacological therapy for chronic obstructive pulmonary disease (COPD)

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic lung condition characterised by persistent respiratory symptoms and limited lung airflow, dyspnoea and recurrent exacerbations. Suboptimal therapy or non-adherence may result in limited effectiveness of pharmacological treatments and subsequently poor health outcomes.

OBJECTIVES

To determine the efficacy and safety of interventions intended to improve adherence to single or combined pharmacological treatments compared with usual care or interventions that are not intended to improve adherence in people with COPD.

SEARCH METHODS

We identified randomised controlled trials (RCTs) from the Cochrane Airways Trials Register, CENTRAL, MEDLINE and Embase (search date 1 May 2020). We also searched web-based clinical trial registers.

SELECTION CRITERIA

RCTs included adults with COPD diagnosed by established criteria (e.g. Global Initiative for Obstructive Lung Disease). Interventions included change to pharmacological treatment regimens, adherence aids, education, behavioural or psychological interventions (e.g. cognitive behavioural therapy), communication or follow-up by a health professional (e.g. telephone, text message or face-to-face), multi-component interventions, and interventions to improve inhaler technique.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Working in pairs, four review authors independently selected trials for inclusion, extracted data and assessed risk of bias. We assessed confidence in the evidence for each primary outcome using GRADE. Primary outcomes were adherence, quality of life and hospital service utilisation. Adherence measures included the Adherence among Patients with Chronic Disease questionnaire (APCD). Quality of life measures included the St George's Respiratory Questionnaire (SGRQ), COPD Assessment Test (CAT) and Clinical COPD Questionnaire (CCQ).

MAIN RESULTS

We included 14 trials (2191 participants) in the analysis with follow-up ranging from six to 52 weeks. Age ranged from 54 to 75 years, and COPD severity ranged from mild to very severe. Trials were conducted in the USA, Spain, Germany, Japan, Jordan, Northern Ireland, Iran, South Korea, China and Belgium. Risk of bias was high due to lack of blinding. Evidence certainty was downgraded due to imprecision and small participant numbers. Single component interventions Six studies (55 to 212 participants) reported single component interventions including changes to pharmacological treatment (different roflumilast doses or different inhaler types), adherence aids (Bluetooth inhaler reminder device), educational (comprehensive verbal instruction), behavioural or psychological (motivational interview). Change in dose of roflumilast may result in little to no difference in adherence (odds ratio (OR) 0.67, 95% confidence interval (CI) 0.22 to 1.99; studies = 1, participants = 55; low certainty). A Bluetooth inhaler reminder device did not improve adherence, but comprehensive verbal instruction from a health professional did improve mean adherence (prescription refills) (mean difference (MD) 1.00, 95% CI 0.46 to 1.54). Motivational interview improved mean adherence scores on the APCD scale (MD 22.22, 95% CI 8.42 to 36.02). Use of a single inhaler compared to two separate inhalers may have little to no impact on quality of life (SGRQ; MD 0.80, 95% CI -3.12 to 4.72; very low certainty). A Bluetooth inhaler monitoring device may provide a small improvement in quality of life on the CCQ (MD 0.40, 95% CI 0.07 to 0.73; very low certainty). Single inhaler use may have little to no impact on the number of people admitted to hospital compared to two separate inhalers (OR 1.47, 95% CI 0.75 to 2.90; very low certainty). Single component interventions may have little to no impact on the number of people expereincing adverse events (very low certainty evidence from studies of a change in pharmacotherapy or use of adherence aids). A change in pharmacotherapy may have little to no impact on exacerbations or deaths (very low certainty). Multi-component interventions Eight studies (30 to 734 participants) reported multi-component interventions including tailored care package that included adherence support as a key component or included inhaler technique as a component. A multi-component intervention may result in more people adhering to pharmacotherapy compared to control at 40.5 weeks (risk ratio (RR) 1.37, 95% CI 1.18 to 1.59; studies = 4, participants = 446; I2 = 0%; low certainty). There may be little to no impact on quality of life (SGRQ, Chronic Respiratory Disease Questionnaire, CAT) (studies = 3; low to very low certainty). Multi-component interventions may help to reduce the number of people admitted to hospital for any cause (OR 0.37, 95% CI 0.22 to 0.63; studies = 2, participants = 877; low certainty), or COPD-related hospitalisations (OR 0.15, 95% CI 0.07 to 0.34; studies = 2, participants = 220; moderate certainty). There may be a small benefit on people experiencing severe exacerbations. There may be little to no effect on adverse events, serious adverse events or deaths, but events were infrequently reported and were rare (low to very certainty).

AUTHORS' CONCLUSIONS

Single component interventions (e.g. education or motivational interviewing provided by a health professional) can help to improve adherence to pharmacotherapy (low to very low certainty). There were slight improvements in quality of life with a Bluetooth inhaler device, but evidence is from one study and very low certainty. Change to pharmacotherapy (e.g. single inhaler instead of two, or different doses of roflumilast) has little impact on hospitalisations or exacerbations (very low certainty). There is no difference in people experiencing adverse events (all-cause or COPD-related), or deaths (very low certainty). Multi-component interventions may improve adherence with education, motivational or behavioural components delivered by health professionals (low certainty). There is little to no impact on quality of life (low to very low certainty). They may help reduce the number of people admitted to hospital overall (specifically pharmacist-led approaches) (low certainty), and fewer people may have COPD-related hospital admissions (moderately certainty). There may be a small reduction in people experiencing severe exacerbations, but evidence is from one study (low certainty). Limited evidence found no difference in people experiencing adverse events, serious adverse events or deaths (low to very low certainty). The evidence presented should be interpreted with caution. Larger studies with more intervention types, especially single interventions, are needed. It is unclear which specific COPD subgroups would benefit, therefore discussions between health professionals and patients may help to determine whether they will help to improve health outcomes.

The PRISMA 2020 statement: an updated guideline for reporting systematic reviews

The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, published in 2009, was designed to help systematic reviewers transparently report why the review was done, what the authors did, and what they found. Over the past decade, advances in systematic review methodology and terminology have necessitated an update to the guideline. The PRISMA 2020 statement replaces the 2009 statement and includes new reporting guidance that reflects advances in methods to identify, select, appraise, and synthesise studies. The structure and presentation of the items have been modified to facilitate implementation. In this article, we present the PRISMA 2020 27-item checklist, an expanded checklist that details reporting recommendations for each item, the PRISMA 2020 abstract checklist, and the revised flow diagrams for original and updated reviews. Full English text available from:www.revespcardiol.org/en.

Short versus long feeding interval for bolus feedings in very preterm infants

BACKGROUND

There is presently no certainty about the ideal feeding intervals for preterm infants. Shorter feeding intervals of, for example, two hours, have the theoretical advantage of allowing smaller volumes of milk. This may have the potential to reduce the incidence and severity of gastro-oesophageal reflux. Longer feeding intervals have the theoretical advantage of allowing more gastric emptying between two feeds. This potentially provides periods of rest (and thus less hyperaemia) for an immature digestive tract.

OBJECTIVES

To determine the safety of shorter feeding intervals (two hours or shorter) versus longer feeding intervals (three hours or more) and to compare the effects in terms of days taken to regain birth weight and to achieve full feeding.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to run comprehensive searches in CENTRAL (2020, Issue 6) and Ovid MEDLINE and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions, and CINAHL on 25 June 2020. We searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs and quasi-RCTs comparing short (e.g. one or two hours) versus long (e.g. three or four hours) feeding intervals in preterm infants of any birth weight, all or most of whom were less than 32 weeks' gestation. Infants could be of any postnatal age at trial entry, but eligible infants should not have received feeds before study entry, with the exception of minimal enteral feeding. We included studies of nasogastric or orogastric bolus feeding, breast milk or formula, in which the feeding interval is the intervention.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used the GRADE approach to assess the certainty of evidence. Our primary outcomes were days taken to achieve full enteral feeding and days to regain birth weight. Our other outcomes were duration of hospital stay, episodes of necrotising enterocolitis (NEC) and growth during hospital stay (weight, length and head circumference).

MAIN RESULTS

We included four RCTs, involving 417 infants in the review. One study involving 350 infants is awaiting classification. All studies compared two-hourly versus three-hourly feeding interval. The risk of bias of the included studies was generally low, but all studies had high risk of performance bias due to lack of blinding of the intervention. Three studies were included in meta-analysis for the number of days taken to achieve full enteral feeding (351 participants). The mean days to achieve full feeds was between eight and 11 days. There was little or no difference in days taken to achieve full enteral feeding between two-hourly and three-hourly feeding, but this finding was of low certainty (mean difference (MD) ‒0.62, 95% confidence interval (CI) ‒1.60 to 0.36). There was low-certainty evidence that the days taken to regain birth weight may be slightly longer in infants receiving two-hourly feeding than in those receiving three-hourly feeding (MD 1.15, 95% CI 0.11 to 2.20; 3 studies, 350 participants). We are uncertain whether shorter feeding intervals have any effect on any of our secondary outcomes including the duration of hospital stay (MD ‒3.36, 95% CI ‒9.18 to 2.46; 2 studies, 207 participants; very low-certainty evidence) and the risk of NEC (typical risk ratio 1.07, 95% CI 0.54 to 2.11; 4 studies, 417 participants; low-certainty evidence). No study reported growth during hospital stay.

AUTHORS' CONCLUSIONS

The low-certainty evidence we found in this review suggests that there may be no clinically important differences between two- and three-hourly feeding intervals. There is insufficient information about potential feeding complications and in particular NEC. No studies have looked at the effect of other feeding intervals and there is no long-term data on neurodevelopment or growth.

Soap versus sanitiser for preventing the transmission of acute respiratory infections in the community: a systematic review with meta-analysis and dose-response analysis

OBJECTIVE

To compare the effectiveness of hand hygiene using alcohol-based hand sanitiser to soap and water for preventing the transmission of acute respiratory infections (ARIs) and to assess the relationship between the dose of hand hygiene and the number of ARI, influenza-like illness (ILI) or influenza events.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature (CINAHL) and trial registries were searched in April 2020.

INCLUSION CRITERIA

We included randomised controlled trials that compared a community-based hand hygiene intervention (soap and water, or sanitiser) with a control, or trials that compared sanitiser with soap and water, and measured outcomes of ARI, ILI or laboratory-confirmed influenza or related consequences.

DATA EXTRACTION AND ANALYSIS

Two review authors independently screened the titles and abstracts for inclusion and extracted data.

RESULTS

Eighteen trials were included. When meta-analysed, three trials of soap and water versus control found a non-significant increase in ARI events (risk ratio (RR) 1.23, 95% CI 0.78 to 1.93); six trials of sanitiser versus control found a significant reduction in ARI events (RR 0.80, 95% CI 0.71 to 0.89). When hand hygiene dose was plotted against ARI relative risk, no clear dose-response relationship was observable. Four trials were head-to-head comparisons of sanitiser and soap and water but too heterogeneous to pool: two found a significantly greater reduction in the sanitiser group compared with the soap group and two found no significant difference between the intervention arms.

CONCLUSIONS

Adequately performed hand hygiene, with either soap or sanitiser, reduces the risk of ARI virus transmission; however, direct and indirect evidence suggest sanitiser might be more effective in practice.

Supervised maintenance programmes following pulmonary rehabilitation compared to usual care for chronic obstructive pulmonary disease

BACKGROUND

Pulmonary rehabilitation benefits patients with chronic obstructive pulmonary disease (COPD), but gains are not maintained over time. Maintenance pulmonary rehabilitation has been defined as ongoing supervised exercise at a lower frequency than the initial pulmonary rehabilitation programme. It is not yet known whether a maintenance programme can preserve the benefits of pulmonary rehabilitation over time. Studies of maintenance programmes following pulmonary rehabilitation are heterogeneous, especially regarding supervision frequency. Furthermore, new maintenance models (remote and home-based) are emerging.

OBJECTIVES

To determine whether supervised pulmonary rehabilitation maintenance programmes improve health-related quality of life (HRQoL), exercise performance, and health care utilisation in COPD patients compared with usual care. Secondly, to examine in subgroup analyses the impact of supervision frequency and model (remote or in-person) during the supervised maintenance programme.

SEARCH METHODS

We searched the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, PEDro, and two additional trial registries platforms up to 31 March 2020, without restriction by language or type of publication. We screened the reference lists of all primary studies for additional references. We also hand-searched conference abstracts and grey literature through the Cochrane Airways Trials Register and CENTRAL.

SELECTION CRITERIA

We included only randomised trials comparing pulmonary rehabilitation maintenance for COPD with attention control or usual care. The primary outcomes were HRQoL, exercise capacity and hospitalisation; the secondary outcomes were exacerbation rate, mortality, direct costs of care, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts, extracted data, and assessed the risk of bias. Results data that were similar enough to be pooled were meta-analysed using a random-effects model, and those that could not be pooled were reported in narrative form. Subgroup analyses were undertaken for frequency of supervision (programmes offered monthly or less frequently, versus more frequently) and those using remote supervision (e.g. telerehabilitation versus face-to-face supervision). We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 21 studies (39 reports) with 1799 COPD patients. Participants ranged in age from 52 years to 88 years. Disease severity ranged from 24% to 88% of the predicted forced expiratory volume in one second. Programme duration ranged from four weeks to 36 months. In-person supervision was provided in 12 studies, and remote supervision was provided in six studies (telephone or web platform). Four studies provided a combination of in-person and remote supervision. Most studies had a high risk of performance bias due to lack of blinding of participants, and high risk of detection, attrition, and reporting bias. Low- to moderate-certainty evidence showed that supervised maintenance programmes may improve health-related quality of life at six to 12 months following pulmonary rehabilitation compared to usual care (Chronic Respiratory Questionnaire total score mean difference (MD) 0.54 points, 95% confidence interval (CI) 0.04 to 1.03, 258 participants, four studies), with a mean difference that exceeded the minimal important difference of 0.5 points for this outcome. It is possible that supervised maintenance could improve six-minute walk distance, but this is uncertain (MD 26 metres (m), 95% CI -1.04 to 52.84, 639 participants, 10 studies). There was little to no difference between the maintenance programme and the usual care group in exacerbations or all-cause hospitalizations, or the chance of death (odds ratio (OR) for mortality 0.73, 95% CI 0.36 to 1.51, 755 participants, six studies). Insufficient data were available to understand the impact of the frequency of supervision, or of remote versus in-person supervision. No adverse events were reported.

AUTHORS' CONCLUSIONS

This review suggests that supervised maintenance programmes for COPD patients after pulmonary rehabilitation are not associated with increased adverse events, may improve health-related quality of life, and could possibly improve exercise capacity at six to 12 months. Effects on exacerbations, hospitalisation and mortality are similar to those of usual care. However, the strength of evidence was limited because most included studies had a high risk of bias and small sample size. The optimal supervision frequency and models for supervised maintenance programmes are still unclear.

Continuous versus bolus intermittent intragastric tube feeding for preterm and low birth weight infants with gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease is a particularly common condition among preterm and low birth weight infants. These infants are more likely to have excessive regurgitation, as they do not have a fully developed antireflux mechanism. Preterm and low birth weight infants who are unable to suck oral feeds are required to be fed via an intragastric tube for varying lengths of time. Intragastric tube feeding can be delivered by the intermittent bolus method or by the continuous feeding method. Use of continuous or intermittent bolus intragastric feeding may have a positive or negative effect on the incidence or severity of gastro-oesophageal reflux disease.

OBJECTIVES

• To determine whether continuous or intermittent bolus intragastric tube feeding reduces the number of episodes and the duration of gastro-oesophageal reflux disease (GORD) in preterm and low birth weight infants • To perform subgroup analyses for gestational age; birth weight; age in days from birth at full enteral feeding via intragastric tube (breast versus bottle); frequency of intermittent bolus feed; and type of medication for treatment of GORD (only if medication was prescribed and was given similarly to both intervention groups) SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 7), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), on 8 July 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

Published and unpublished RCTs and quasi-RCTs were eligible for inclusion in this review, as were cluster-randomised and cross-over randomised trials that compared the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and quality. We planned to use the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We found no trials that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We did not identify any randomised trials that evaluated the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants. Well-designed and adequately powered trials are needed.

Tailored or adapted interventions for adults with chronic obstructive pulmonary disease and at least one other long-term condition: a mixed methods review

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition characterised by shortness of breath, cough and recurrent exacerbations. People with COPD often live with one or more co-existing long-term health conditions (comorbidities). People with more severe COPD often have a higher number of comorbidities, putting them at greater risk of morbidity and mortality.

OBJECTIVES

To assess the effectiveness of any single intervention for COPD adapted or tailored to their comorbidity(s) compared to any other intervention for people with COPD and one or more common comorbidities (quantitative data, RCTs) in terms of the following outcomes: Quality of life, exacerbations, functional status, all-cause and respiratory-related hospital admissions, mortality, pain, and depression and anxiety. To assess the effectiveness of an adapted or tailored single COPD intervention (simple or complex) that is aimed at changing the management of people with COPD and one or more common comorbidities (quantitative data, RCTs) compared to usual care in terms of the following outcomes: Quality of life, exacerbations, functional status, all-cause and respiratory-related hospital admissions, mortality, pain, and depression and anxiety. To identify emerging themes that describe the views and experiences of patients, carers and healthcare professionals when receiving or providing care to manage multimorbidities (qualitative data).

SEARCH METHODS

We searched multiple databases including the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, and CINAHL, to identify relevant randomised and qualitative studies. We also searched trial registries and conducted citation searches. The latest search was conducted in January 2021.

SELECTION CRITERIA

Eligible randomised controlled trials (RCTs) compared a) any single intervention for COPD adapted or tailored to their comorbidity(s) compared to any other intervention, or b) any adapted or tailored single COPD intervention (simple or complex) that is aimed at changing the management of people with COPD and one or more comorbidities, compared to usual care. We included qualitative studies or mixed-methods studies to identify themes.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods for analysis of the RCTs. We used Cochrane's risk of bias tool for the RCTs and the CASP checklist for the qualitative studies. We planned to use the Mixed Methods Appraisal tool (MMAT) to assess the risk of bias in mixed-methods studies, but we found none. We used GRADE and CERQual to assess the quality of the quantitative and qualitative evidence respectively. The primary outcome measures for this review were quality of life and exacerbations.

MAIN RESULTS

Quantitative studies We included seven studies (1197 participants) in the quantitative analyses, with interventions including telemonitoring, pulmonary rehabilitation, treatment optimisation, water-based exercise training and case management. Interventions were either compared with usual care or with an active comparator (such as land-based exercise training). Duration of trials ranged from 4 to 52 weeks. Mean age of participants ranged from 64 to 72 years and COPD severity ranged from mild to very severe. Trials included either people with COPD and a specific comorbidity (including cardiovascular disease, metabolic syndrome, lung cancer, head or neck cancer, and musculoskeletal conditions), or with one or more comorbidities of any type. Overall, we judged the evidence presented to be of moderate to very low certainty (GRADE), mainly due to the methodological quality of included trials and imprecision of effect estimates. Intervention versus usual care Quality of life as measured by the St George's Respiratory Questionnaire (SGRQ) total score may improve with tailored pulmonary rehabilitation compared to usual care at 52 weeks (mean difference (MD) -10.85, 95% confidence interval (CI) -12.66 to -9.04; 1 study, 70 participants; low-certainty evidence). Tailored pulmonary rehabilitation is likely to improve COPD assessment test (CAT) scores compared with usual care at 52 weeks (MD -8.02, 95% CI -9.44 to -6.60; 1 study, 70 participants, moderate-certainty evidence) and with a multicomponent telehealth intervention at 52 weeks (MD -6.90, 95% CI -9.56 to -4.24; moderate-certainty evidence). Evidence is uncertain about effects of pharmacotherapy optimisation or telemonitoring interventions on CAT improvement compared with usual care. There may be little to no difference in the number of people experiencing exacerbations, or mean exacerbations with case management compared with usual care (OR 1.09, 95% CI 0.75 to 1.57; 1 study, 470 participants; very low-certainty evidence). For secondary outcomes, six-minute walk distance (6MWD) may improve with pulmonary rehabilitation, water-based exercise or multicomponent interventions at 38 to 52 weeks (low-certainty evidence). A multicomponent intervention may result in fewer people being admitted to hospital at 17 weeks, although there may be little to no difference in a telemonitoring intervention. There may be little to no difference between intervention and usual care for mortality. Intervention versus active comparator We included one study comparing water-based and land-based exercise (30 participants). We found no evidence for quality of life or exacerbations. There may be little to no difference between water- and land-based exercise for 6MWD (MD 5 metres, 95% CI -22 to 32; 38 participants; very low-certainty evidence). Qualitative studies One nested qualitative study (21 participants) explored perceptions and experiences of people with COPD and long-term conditions, and of researchers and health professionals who were involved in an RCT of telemonitoring equipment. Several themes were identified, including health status, beliefs and concerns, reliability of equipment, self-efficacy, perceived ease of use, factors affecting usefulness and perceived usefulness, attitudes and intention, self-management and changes in healthcare use. We judged the qualitative evidence presented as of very low certainty overall.

AUTHORS' CONCLUSIONS

Owing to a paucity of eligible trials, as well as diversity in the intervention type, comorbidities and the outcome measures reported, we were unable to provide a robust synthesis of data. Pulmonary rehabilitation or multicomponent interventions may improve quality of life and functional status (6MWD), but the evidence is too limited to draw a robust conclusion. The key take-home message from this review is the lack of data from RCTs on treatments for people living with COPD and comorbidities. Given the variation in number and type of comorbidity(s) an individual may have, and severity of COPD, larger studies reporting individual patient data are required to determine these effects.

Interventions for the prevention of persistent post-COVID-19 olfactory dysfunction

BACKGROUND

Loss of olfactory function is well recognised as a cardinal symptom of COVID-19 infection, and the ongoing pandemic has resulted in a large number of affected individuals with abnormalities in their sense of smell. For many, the condition is temporary and resolves within two to four weeks. However, in a significant minority the symptoms persist. At present, it is not known whether early intervention with any form of treatment (such as medication or olfactory training) can promote recovery and prevent persisting olfactory disturbance.  OBJECTIVES: To assess the effects (benefits and harms) of interventions that have been used, or proposed, to prevent persisting olfactory dysfunction due to COVID-19 infection. A secondary objective is to keep the evidence up-to-date, using a living systematic review approach.  SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane COVID-19 Study Register; Cochrane ENT Register; CENTRAL; Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished studies. The date of the search was 16 December 2020.

SELECTION CRITERIA

Randomised controlled trials including participants who had symptoms of olfactory disturbance following COVID-19 infection. Individuals who had symptoms for less than four weeks were included in this review. Studies compared any intervention with no treatment or placebo.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. Our primary outcomes were the presence of normal olfactory function, serious adverse effects and change in sense of smell. Secondary outcomes were the prevalence of parosmia, change in sense of taste, disease-related quality of life and other adverse effects (including nosebleeds/bloody discharge). We used GRADE to assess the certainty of the evidence for each outcome.  MAIN RESULTS: We included one study of 100 participants, which compared an intranasal steroid spray to no intervention. Participants in both groups were also advised to undertake olfactory training for the duration of the trial. Data were identified for only two of the prespecified outcomes for this review, and no data were available for the primary outcome of serious adverse effects. Intranasal corticosteroids compared to no intervention (all using olfactory training) Presence of normal olfactory function after three weeks of treatment was self-assessed by the participants, using a visual analogue scale (range 0 to 10, higher scores = better). A score of 10 represented "completely normal smell sensation". The evidence is very uncertain about the effect of intranasal corticosteroids on self-rated recovery of sense of smell (estimated absolute effect 619 per 1000 compared to 520 per 1000, risk ratio (RR) 1.19, 95% confidence interval (CI) 0.85 to 1.68; 1 study; 100 participants; very low-certainty evidence).  Change in sense of smell was not reported, but the self-rated score for sense of smell was reported at the endpoint of the study with the same visual analogue scale (after three weeks of treatment). The median scores at endpoint were 10 (interquartile range (IQR) 9 to 10) for the group receiving intranasal corticosteroids, and 10 (IQR 5 to 10) for the group receiving no intervention (1 study; 100 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

There is very limited evidence regarding the efficacy of different interventions at preventing persistent olfactory dysfunction following COVID-19 infection. However, we have identified a small number of additional ongoing studies in this area. As this is a living systematic review, the evidence will be updated regularly to incorporate new data from these, and other relevant studies, as they become available.  For this (first) version of the living review, we identified a single study of intranasal corticosteroids to include in this review, which provided data for only two of our prespecified outcomes. The evidence was of very low certainty, therefore we were unable to determine whether intranasal corticosteroids may have a beneficial or harmful effect.

Interventions for the treatment of persistent post-COVID-19 olfactory dysfunction

BACKGROUND

Olfactory dysfunction is an early and sensitive marker of COVID-19 infection. Although self-limiting in the majority of cases, when hyposmia or anosmia persists it can have a profound effect on quality of life. Little guidance exists on the treatment of post-COVID-19 olfactory dysfunction, however several strategies have been proposed from the evidence relating to the treatment of post-viral anosmia (such as medication or olfactory training).

OBJECTIVES

To assess the effects (benefits and harms) of interventions that have been used, or proposed, to treat persisting olfactory dysfunction due to COVID-19 infection. A secondary objective is to keep the evidence up-to-date, using a living systematic review approach.  SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane COVID-19 Study Register; Cochrane ENT Register; CENTRAL; Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished studies. The date of the search was 16 December 2020.

SELECTION CRITERIA

Randomised controlled trials including participants who had symptoms of olfactory disturbance following COVID-19 infection. Only individuals who had symptoms for at least four weeks were included in this review. Studies compared any intervention with no treatment or placebo.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Primary outcomes were the recovery of sense of smell, disease-related quality of life and serious adverse effects. Secondary outcomes were the change in sense of smell, general quality of life, prevalence of parosmia and other adverse effects (including nosebleeds/bloody discharge). We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included one study with 18 participants, which compared the use of a 15-day course of oral steroids combined with nasal irrigation (consisting of an intranasal steroid/mucolytic/decongestant solution) with no intervention. Psychophysical testing was used to assess olfactory function at baseline, 20 and 40 days. Systemic corticosteroids plus intranasal steroid/mucolytic/decongestant compared to no intervention Recovery of sense of smell was assessed after 40 days (25 days after cessation of treatment) using the Connecticut Chemosensory Clinical Research Center (CCCRC) score. This tool has a range of 0 to 100, and a score of ≥ 90 represents normal olfactory function. The evidence is very uncertain about the effect of this intervention on recovery of the sense of smell at one to three months (5/9 participants in the intervention group scored ≥ 90 compared to 0/9 in the control group; risk ratio (RR) 11.00, 95% confidence interval (CI) 0.70 to 173.66; 1 study; 18 participants; very low-certainty evidence). Change in sense of smell was assessed using the CCCRC score at 40 days. This study reported an improvement in sense of smell in the intervention group from baseline (median improvement in CCCRC score 60, interquartile range (IQR) 40) compared to the control group (median improvement in CCCRC score 30, IQR 25) (1 study; 18 participants; very low-certainty evidence). Serious adverse events andother adverse events were not identified in any participants of this study; however, it is unclear how these outcomes were assessed and recorded (1 study; 18 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

There is very limited evidence available on the efficacy and harms of treatments for persistent olfactory dysfunction following COVID-19 infection. However, we have identified other ongoing trials in this area. As this is a living systematic review we will update the data regularly, as new results become available. For this (first) version of the living review we identified only one study with a small sample size, which assessed systemic steroids and nasal irrigation (intranasal steroid/mucolytic/decongestant). However, the evidence regarding the benefits and harms from this intervention to treat persistent post-COVID-19 olfactory dysfunction is very uncertain.

Opioid treatment for opioid withdrawal in newborn infants

BACKGROUND

Neonatal abstinence syndrome (NAS) due to opioid withdrawal may result in disruption of the mother-infant relationship, sleep-wake abnormalities, feeding difficulties, weight loss, seizures and neurodevelopmental problems.

OBJECTIVES

To assess the effectiveness and safety of using an opioid for treatment of NAS due to withdrawal from opioids in newborn infants.

SEARCH METHODS

We ran an updated search on 17 September 2020 in CENTRAL via Cochrane Register of Studies Web and MEDLINE via Ovid. We also searched clinical trials databases, conference proceedings and the reference lists of retrieved articles for eligible trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), quasi- and cluster-RCTs which enrolled infants born to mothers with opioid dependence and who were experiencing NAS requiring treatment with an opioid.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trial eligibility and risk of bias, and independently extracted data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 16 trials (1110 infants) with NAS secondary to maternal opioid use in pregnancy. Seven studies at low risk of bias were included in sensitivity analysis. Opioid versus no treatment / usual care: a single trial (80 infants) of morphine and supportive care versus supportive care alone reported no difference in treatment failure (risk ratio (RR) 1.29, 95% confidence interval (CI) 0.41 to 4.07; very low certainty evidence). No infant had a seizure. The trial did not report mortality, neurodevelopmental disability and adverse events. Morphine increased days hospitalisation (mean difference (MD) 15.00, 95% CI 8.86 to 21.14; very low certainty evidence) and treatment (MD 12.50, 95% CI 7.52 to 17.48; very low certainty evidence), but decreased days to regain birthweight (MD -2.80, 95% CI -5.33 to -0.27) and duration (minutes) of supportive care each day (MD -197.20, 95% CI -274.15 to -120.25). Morphine versus methadone: there was no difference in treatment failure (RR 1.59, 95% CI 0.95 to 2.67; 2 studies, 147 infants; low certainty evidence). Seizures, neonatal or infant mortality and neurodevelopmental disability were not reported. A single study reported no difference in days hospitalisation (MD 1.40, 95% CI -3.08 to 5.88; 116 infants; low certainty evidence), whereas data from two studies found an increase in days treatment (MD 2.71, 95% CI 0.22 to 5.21; 147 infants; low certainty) for infants treated with morphine. A single study reported no difference in breastfeeding, adverse events, or out of home placement. Morphine versus sublingual buprenorphine: there was no difference in treatment failure (RR 0.79, 95% CI 0.36 to 1.74; 3 studies, 113 infants; very low certainty evidence). Neonatal or infant mortality and neurodevelopmental disability were not reported. There was moderate certainty evidence of an increase in days hospitalisation (MD 11.45, 95% CI 5.89 to 17.01; 3 studies, 113 infants), and days treatment (MD 12.79, 95% CI 7.57 to 18.00; 3 studies, 112 infants) for infants treated with morphine. A single adverse event (seizure) was reported in infants exposed to buprenorphine. Morphine versus diluted tincture of opium (DTO): a single study (33 infants) reported no difference in days hospitalisation, days treatment or weight gain (low certainty evidence). Opioid versus clonidine: a single study (31 infants) reported no infant with treatment failure in either group. This study did not report seizures, neonatal or infant mortality and neurodevelopmental disability. There was low certainty evidence for no difference in days hospitalisation or days treatment. This study did not report adverse events. Opioid versus diazepam: there was a reduction in treatment failure from use of an opioid (RR 0.43, 95% CI 0.23 to 0.80; 2 studies, 86 infants; low certainty evidence). Seizures, neonatal or infant mortality and neurodevelopmental disability were not reported. A single study of 34 infants comparing methadone versus diazepam reported no difference in days hospitalisation or days treatment (very low certainty evidence). Adverse events were not reported. Opioid versus phenobarbital: there was a reduction in treatment failure from use of an opioid (RR 0.51, 95% CI 0.35 to 0.74; 6 studies, 458 infants; moderate certainty evidence). Subgroup analysis found a reduction in treatment failure in trials titrating morphine to ≧ 0.5 mg/kg/day (RR 0.21, 95% CI 0.10 to 0.45; 3 studies, 230 infants), whereas a single study using morphine < 0.5 mg/kg/day reported no difference compared to use of phenobarbital (subgroup difference P = 0.05). Neonatal or infant mortality and neurodevelopmental disability were not reported. A single study (111 infants) of paregoric versus phenobarbital reported seven infants with seizures in the phenobarbital group, whereas no seizures were reported in two studies (170 infants) comparing morphine to phenobarbital. There was no difference in days hospitalisation or days treatment. A single study (96 infants) reported no adverse events in either group. Opioid versus chlorpromazine: there was a reduction in treatment failure from use of morphine versus chlorpromazine (RR 0.08, 95% CI 0.01 to 0.62; 1 study, 90 infants; moderate certainty evidence). No seizures were reported in either group. There was low certainty evidence for no difference in days treatment. This trial reported no adverse events in either group. None of the included studies reported time to control of NAS. Data for duration and severity of NAS were limited, and we were unable to use these data in quantitative synthesis.

AUTHORS' CONCLUSIONS

Compared to supportive care alone, the addition of an opioid may increase duration of hospitalisation and treatment, but may reduce days to regain birthweight and the duration of supportive care each day. Use of an opioid may reduce treatment failure compared to phenobarbital, diazepam or chlorpromazine. Use of an opioid may have little or no effect on duration of hospitalisation or treatment compared to use of phenobarbital, diazepam or chlorpromazine. The type of opioid used may have little or no effect on the treatment failure rate. Use of buprenorphine probably reduces duration of hospitalisation and treatment compared to morphine, but there are no data for time to control NAS with buprenorphine, and insufficient evidence to determine safety. There is insufficient evidence to determine the effectiveness and safety of clonidine.

State of the evidence: a survey of global disparities in clinical trials

Introduction

Ideally, health conditions causing the greatest global disease burden should attract increased research attention. We conducted a comprehensive global study investigating the number of randomised controlled trials (RCTs) published on different health conditions, and how this compares with the global disease burden that they impose.

Methods

We use machine learning to monitor PubMed daily, and find and analyse RCT reports. We assessed RCTs investigating the leading causes of morbidity and mortality from the Global Burden of Disease study. Using regression models, we compared numbers of actual RCTs in different health conditions to numbers predicted from their global disease burden (disability-adjusted life years (DALYs)). We investigated whether RCT numbers differed for conditions disproportionately affecting countries with lower socioeconomic development.

Results

We estimate 463 000 articles describing RCTs (95% prediction interval 439 000 to 485 000) were published from 1990 to July 2020. RCTs recruited a median of 72 participants (IQR 32–195). 82% of RCTs were conducted by researchers in the top fifth of countries by socio-economic development. As DALYs increased for a particular health condition by 10%, the number of RCTs in the same year increased by 5% (3.2%–6.9%), but the association was weak (adjusted R²=0.13). Conditions disproportionately affecting countries with lower socioeconomic development, including respiratory infections and tuberculosis (7000 RCTs below predicted) and enteric infections (9700 RCTs below predicted), appear relatively under-researched for their disease burden. Each 10% shift in DALYs towards countries with low and middle socioeconomic development was associated with a 4% reduction in RCTs (3.7%–4.9%). These disparities have not changed substantially over time.

Conclusion

Research priorities are not well optimised to reduce the global burden of disease. Most RCTs are produced by highly developed countries, and the health needs of these countries have been, on average, favoured.

Continuous nasogastric milk feeding versus intermittent bolus milk feeding for preterm infants less than 1500 grams

BACKGROUND

Milk feedings can be given via nasogastric tube either intermittently, typically over 10 to 20 minutes every two or three hours, or continuously, using an infusion pump. Although the theoretical benefits and risks of each method have been proposed, their effects on clinically important outcomes remain uncertain.  OBJECTIVES: To examine the evidence regarding the effectiveness of continuous versus intermittent bolus tube feeding of milk in preterm infants less than 1500 grams.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to run comprehensive searches in the Cochrane Central Register of Controlled Trials (CENTRAL 2020, Issue 7) in the Cochrane Library; Ovid MEDLINE and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions; and CINAHL (Cumulative Index to Nursing and Allied Health Literature) on 17 July 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs and quasi-RCTs comparing continuous versus intermittent bolus nasogastric milk feeding in preterm infants less than 1500 grams.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all trials for relevance and risk of bias. We used the standard methods of Cochrane Neonatal to extract data. We used the GRADE approach to assess the certainty of evidence. Primary outcomes were: age at full enteral feedings; feeding intolerance; days to regain birth weight; rate of gain in weight, length and head circumference; and risk of necrotising enterocolitis (NEC).

MAIN RESULTS

We included nine randomised trials (919 infants) in this updated Cochrane Review. One study is awaiting classification. Seven of the nine included trials reported data from infants with a maximum weight of between 1000 grams and 1400 grams. Two of the nine trials included infants weighing up to 1500 grams. Type(s) of milk feeds varied, including human milk (either mother's own milk or pasteurised donor human milk), preterm formula, or mixed feeding regimens. In some instances, preterm formula was initially diluted. Earlier studies also used water to initiate feedings. We judged six trials as unclear or high risk of bias for random sequence generation. We judged four trials as unclear for allocation concealment. We judged all trials as high risk of bias for blinding of care givers, and seven as unclear or high risk of bias for blinding of outcome assessors. We downgraded the certainty of evidence for imprecision, due to low numbers of participants in the trials, and/or wide 95% confidence intervals, and/or for risk of bias. Continuous compared to intermittent bolus (nasogastric and orogastric tube) milk feeding Babies receiving continuous feeding may reach full enteral feeding almost one day later than babies receiving intermittent feeding (mean difference (MD) 0.84 days, 95% confidence interval (CI) -0.13 to 1.81; 7 studies, 628 infants; low-certainty evidence).  It is uncertain if there is any difference between continuous feeding and intermittent feeding in terms of number of days of feeding interruptions (MD -3.00 days, 95% CI -9.50 to 3.50; 1 study, 171 infants; very low-certainty evidence). It is uncertain if continuous feeding has any effect on days to regain birth weight (MD -0.38 days, 95% CI -1.16 to 0.41; 6 studies, 610 infants; low-certainty evidence). The certainty of evidence is low and the 95% confidence interval is consistent with possible benefit and possible harm. It is uncertain if continuous feeding has any effect on rate of gain in weight compared with intermittent feeding (standardised mean difference (SMD) 0.09, 95% CI -0.27 to 0.46; 5 studies, 433 infants; very low-certainty evidence). Continuous feeding may result in little to no difference in rate of gain in length compared with intermittent feeding (MD 0.02 cm/week, 95% CI -0.04 to 0.08; 5 studies, 433 infants; low-certainty evidence). Continuous feeding may result in little to no difference in rate of gain in head circumference compared with intermittent feeding (MD 0.01 cm/week, 95% CI -0.03 to 0.05; 5 studies, 433 infants; low-certainty evidence). It is uncertain if continuous feeding has any effect on the risk of NEC compared with intermittent feeding (RR 1.19, 95% CI 0.67 to 2.11; 4 studies, 372 infants; low-certainty evidence). The certainty of evidence is low and the 95% confidence interval is consistent with possible benefit and possible harm.

AUTHORS' CONCLUSIONS

Although babies receiving continuous feeding may reach full enteral feeding slightly later than babies receiving intermittent feeding, the evidence is of low certainty. However, the clinical risks and benefits of continuous and intermittent nasogastric tube milk feeding cannot be reliably discerned from current available randomised trials. Further research is needed to determine if either feeding method is more appropriate for the initiation of feeds. A rigorous methodology should be adopted, defining feeding protocols and feeding intolerance consistently for all infants. Infants should be stratified according to birth weight and gestation, and possibly according to illness.

Sedatives for opioid withdrawal in newborn infants

BACKGROUND

Neonatal abstinence syndrome (NAS) due to opioid withdrawal may result in disruption of the mother-infant relationship, sleep-wake abnormalities, feeding difficulties, weight loss, seizures and neurodevelopmental problems.

OBJECTIVES

To assess the effectiveness and safety of using a sedative versus control (placebo, usual treatment or non-pharmacological treatment) for NAS due to withdrawal from opioids and determine which type of sedative is most effective and safe for NAS due to withdrawal from opioids.

SEARCH METHODS

We ran an updated search on 17 September 2020 in CENTRAL via CRS Web and MEDLINE via Ovid. We searched clinical trials databases, conference proceedings and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included trials enrolling infants with NAS born to mothers with an opioid dependence with more than 80% follow-up and using randomised, quasi-randomised and cluster-randomised allocation to sedative or control.

DATA COLLECTION AND ANALYSIS

Three review authors assessed trial eligibility and risk of bias, and independently extracted data. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included 10 trials (581 infants) with NAS secondary to maternal opioid use in pregnancy. There were multiple comparisons of different sedatives and regimens. There were limited data available for use in sensitivity analysis of studies at low risk of bias. Phenobarbital versus supportive care: one study reported there may be little or no difference in treatment failure with phenobarbital and supportive care versus supportive care alone (risk ratio (RR) 2.73, 95% confidence interval (CI) 0.94 to 7.94; 62 participants; very low-certainty evidence). No infant had a clinical seizure. The study did not report mortality, neurodevelopmental disability and adverse events. There may be an increase in days' hospitalisation and treatment from use of phenobarbital (hospitalisation: mean difference (MD) 20.80, 95% CI 13.64 to 27.96; treatment: MD 17.90, 95% CI 11.98 to 23.82; both 62 participants; very low-certainty evidence). Phenobarbital versus diazepam: there may be a reduction in treatment failure with phenobarbital versus diazepam (RR 0.39, 95% CI 0.24 to 0.62; 139 participants; 2 studies; low-certainty evidence). The studies did not report mortality, neurodevelopmental disability and adverse events. One study reported there may be little or no difference in days' hospitalisation and treatment (hospitalisation: MD 3.89, 95% CI -1.20 to 8.98; 32 participants; treatment: MD 4.30, 95% CI -0.73 to 9.33; 31 participants; both low-certainty evidence). Phenobarbital versus chlorpromazine: there may be a reduction in treatment failure with phenobarbital versus chlorpromazine (RR 0.55, 95% CI 0.33 to 0.92; 138 participants; 2 studies; very low-certainty evidence), and no infant had a seizure. The studies did not report mortality and neurodevelopmental disability. One study reported there may be little or no difference in days' hospitalisation (MD 7.00, 95% CI -3.51 to 17.51; 87 participants; low-certainty evidence) and 0/100 infants had an adverse event. Phenobarbital and opioid versus opioid alone: one study reported no infants with treatment failure and no clinical seizures in either group (low-certainty evidence). The study did not report mortality, neurodevelopmental disability and adverse events. One study reported there may be a reduction in days' hospitalisation for infants treated with phenobarbital and opioid (MD -43.50, 95% CI -59.18 to -27.82; 20 participants; low-certainty evidence). Clonidine and opioid versus opioid alone: one study reported there may be little or no difference in treatment failure with clonidine and dilute tincture of opium (DTO) versus DTO alone (RR 0.09, 95% CI 0.01 to 1.59; 80 participants; very low-certainty evidence). All five infants with treatment failure were in the DTO group. There may be little or no difference in seizures (RR 0.14, 95% CI 0.01 to 2.68; 80 participants; very low-certainty evidence). All three infants with seizures were in the DTO group. There may be little or no difference in mortality after discharge (RR 7.00, 95% CI 0.37 to 131.28; 80 participants; very low-certainty evidence). All three deaths were in the clonidine and DTO group. The study did not report neurodevelopmental disability. There may be little or no difference in days' treatment (MD -4.00, 95% CI -8.33 to 0.33; 80 participants; very low-certainty evidence). One adverse event occurred in the clonidine and DTO group. There may be little or no difference in rebound NAS after stopping treatment, although all seven cases were in the clonidine and DTO group. Clonidine and opioid versus phenobarbital and opioid: there may be little or no difference in treatment failure (RR 2.27, 95% CI 0.98 to 5.25; 2 studies, 93 participants; very low-certainty evidence). One study reported one infant in the clonidine and morphine group had a seizure, and there were no infant mortalities. The studies did not report neurodevelopmental disability. There may be an increase in days' hospitalisation and days' treatment with clonidine and opioid versus phenobarbital and opioid(hospitalisation: MD 7.13, 95% CI 6.38 to 7.88; treatment: MD 7.57, 95% CI 3.97 to 11.17; both 2 studies, 91 participants; low-certainty evidence). There may be little or no difference in adverse events (RR 1.55, 95% CI 0.44 to 5.40; 2 studies, 93 participants; very low-certainty evidence). However, there was oversedation only in the phenobarbital and morphine group; and hypotension, rebound hypertension and rebound NAS only in the clonidine and morphine group.

AUTHORS' CONCLUSIONS

There is very low-certainty evidence that phenobarbital increases duration of hospitalisation and treatment, but reduces days to regain birthweight and duration of supportive care each day compared to supportive care alone. There is low-certainty evidence that phenobarbital reduces treatment failure compared to diazepam and very low-certainty evidence that  phenobarbital reduces treatment failure compared to chlorpromazine. There is low-certainty evidence of an increase in days' hospitalisation and days' treatment with clonidine and opioid compared to phenobarbital and opioid. There are insufficient data to determine the safety and incidence of adverse events for infants treated with combinations of opioids and sedatives including phenobarbital and clonidine.

Pharmacological and surgical interventions for the treatment of gastro-oesophageal reflux in adults and children with asthma

BACKGROUND

Asthma and gastro-oesophageal reflux disease (GORD) are common medical conditions that frequently co-exist. GORD has been postulated as a trigger for asthma; however, evidence remains conflicting. Proposed mechanisms by which GORD causes asthma include direct airway irritation from micro-aspiration and vagally mediated oesophagobronchial reflux. Furthermore, asthma might precipitate GORD. Thus a temporal association between the two does not establish that GORD triggers asthma.

OBJECTIVES

To evaluate the effectiveness of GORD treatment in adults and children with asthma, in terms of its benefits for asthma.

SEARCH METHODS

The Cochrane Airways Group Specialised Register, CENTRAL, MEDLINE, Embase, reference lists of articles, and online clinical trial databases were searched. The most recent search was conducted on 23 June 2020.

SELECTION CRITERIA

We included randomised controlled trials comparing treatment of GORD in adults and children with a diagnosis of both asthma and GORD versus no treatment or placebo.

DATA COLLECTION AND ANALYSIS

A combination of two independent review authors extracted study data and assessed trial quality. The primary outcome of interest for this review was acute asthma exacerbation as reported by trialists.

MAIN RESULTS

The systematic search yielded a total of 3354 citations; 23 studies (n = 2872 participants) were suitable for inclusion. Included studies reported data from participants in 25 different countries across Europe, North and South America, Asia, Australia, and the Middle East. Participants included in this review had moderate to severe asthma and a diagnosis of GORD and were predominantly adults presenting to a clinic for treatment. Only two studies assessed effects of intervention on children, and two assessed the impact of surgical intervention. The remainder were concerned with medical intervention using a variety of dosing protocols. There was an uncertain reduction in the number of participants experiencing one or more moderate/severe asthma exacerbations with medical treatment for GORD (odds ratio 0.53, 95% confidence interval (CI) 0.17 to 1.63; 1168 participants, 2 studies; low-certainty evidence). None of the included studies reported data related to the other primary outcomes for this review: hospital admissions, emergency department visits, and unscheduled doctor visits. Medical treatment for GORD probably improved forced expiratory volume in one second (FEV₁) by a small amount (mean difference (MD) 0.10 L, 95% CI 0.05 to 0.15; 1333 participants, 7 studies; moderate-certainty evidence) as well as use of rescue medications (MD -0.71 puffs per day, 95% CI -1.20 to -0.22; 239 participants, 2 studies; moderate-certainty evidence). However, the benefit of GORD treatment for morning peak expiratory flow rate was uncertain (MD 6.02 L/min, 95% CI 0.56 to 11.47; 1262 participants, 5 studies). It is important to note that these mean improvements did not reach clinical importance. The benefit of GORD treatment for outcomes synthesised narratively including benefits of treatment for asthma symptoms, quality of life, and treatment preference was likewise uncertain. Data related to adverse events with intervention were generally underreported by the included studies, and those that were available indicated similar rates regardless of allocation to treatment or placebo.

AUTHORS' CONCLUSIONS

Effects of GORD treatment on the primary outcomes of number of people experiencing one or more exacerbations and hospital utilisation remain uncertain. Medical treatment for GORD in people with asthma may provide small benefit for a number of secondary outcomes related to asthma management. This review determined with moderate certainty that with treatment, lung function measures improved slightly, and use of rescue medications for asthma control was reduced. Further, evidence is insufficient to assess results in children, or to compare surgery versus medical therapy.

Generating (Factual?) Narrative Summaries of RCTs: Experiments with Neural Multi-Document Summarization

We consider the problem of automatically generating a narrative biomedical evidence summary from multiple trial reports. We evaluate modern neural models for abstractive summarization of relevant article abstracts from systematic reviews previously conducted by members of the Cochrane collaboration, using the authors conclusions section of the review abstract as our target. We enlist medical professionals to evaluate generated summaries, and we find that summarization systems yield consistently fluent and relevant synopses, but these often contain factual inaccuracies. We propose new approaches that capitalize on domain-specific models to inform summarization, e.g., by explicitly demarcating snippets of inputs that convey key findings, and emphasizing the reports of large and high-quality trials. We find that these strategies modestly improve the factual accuracy of generated summaries. Finally, we propose a new method for automatically evaluating the factuality of generated narrative evidence syntheses using models that infer the directionality of reported findings.

Combination fixed-dose beta agonist and steroid inhaler as required for adults or children with mild asthma

BACKGROUND

Asthma affects 350 million people worldwide including 45% to 70% with mild disease. Treatment is mainly with inhalers containing beta₂-agonists, typically taken as required to relieve bronchospasm, and inhaled corticosteroids (ICS) as regular preventive therapy. Poor adherence to regular therapy is common and increases the risk of exacerbations, morbidity and mortality. Fixed-dose combination inhalers containing both a steroid and a fast-acting beta₂-agonist (FABA) in the same device simplify inhalers regimens and ensure symptomatic relief is accompanied by preventative therapy. Their use is established in moderate asthma, but they may also have potential utility in mild asthma.

OBJECTIVES

To evaluate the efficacy and safety of single combined (fast-onset beta₂-agonist plus an inhaled corticosteroid (ICS)) inhaler only used as needed in people with mild asthma.

SEARCH METHODS

We searched the Cochrane Airways Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase, ClinicalTrials.gov and the World Health Organization (WHO) trials portal. We contacted trial authors for further information and requested details regarding the possibility of unpublished trials. The most recent search was conducted on 19 March 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cross-over trials with at least one week washout period. We included studies of a single fixed-dose FABA/ICS inhaler used as required compared with no treatment, placebo, short-acting beta agonist (SABA) as required, regular ICS with SABA as required, regular fixed-dose combination ICS/long-acting beta agonist (LABA), or regular fixed-dose combination ICS/FABA with as required ICS/FABA. We planned to include cluster-randomised trials if the data had been or could be adjusted for clustering. We excluded trials shorter than 12 weeks. We included full texts, abstracts and unpublished data.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. We analysed dichotomous data as odds ratios (OR) or rate ratios (RR) and continuous data as mean difference (MD). We reported 95% confidence intervals (CIs). We used Cochrane's standard methodological procedures of meta-analysis. We applied the GRADE approach to summarise results and to assess the overall certainty of evidence. Primary outcomes were exacerbations requiring systemic steroids, hospital admissions/emergency department or urgent care visits for asthma, and measures of asthma control.

MAIN RESULTS

We included six studies of which five contributed results to the meta-analyses. All five used budesonide 200 μg and formoterol 6 μg in a dry powder formulation as the combination inhaler. Comparator fast-acting bronchodilators included terbutaline and formoterol. Two studies included children aged 12+ and adults; two studies were open-label. A total of 9657 participants were included, with a mean age of 36 to 43 years. 2.3% to 11% were current smokers. FABA / ICS as required versus FABA as required Compared with as-required FABA alone, as-required FABA/ICS reduced exacerbations requiring systemic steroids (OR 0.45, 95% CI 0.34 to 0.60, 2 RCTs, 2997 participants, high-certainty evidence), equivalent to 109 people out of 1000 in the FABA alone group experiencing an exacerbation requiring systemic steroids, compared to 52 (95% CI 40 to 68) out of 1000 in the FABA/ICS as-required group. FABA/ICS as required may also reduce the odds of an asthma-related hospital admission or emergency department or urgent care visit (OR 0.35, 95% CI 0.20 to 0.60, 2 RCTs, 2997 participants, low-certainty evidence). Compared with as-required FABA alone, any changes in asthma control or spirometry, though favouring as-required FABA/ICS, were small and less than the minimal clinically-important differences. We did not find evidence of differences in asthma-associated quality of life or mortality. For other secondary outcomes FABA/ICS as required was associated with reductions in fractional exhaled nitric oxide, probably reduces the odds of an adverse event (OR 0.82, 95% CI 0.71 to 0.95, 2 RCTs, 3002 participants, moderate-certainty evidence) and may reduce total systemic steroid dose (MD -9.90, 95% CI -19.38 to -0.42, 1 RCT, 443 participants, low-certainty evidence), and with an increase in the daily inhaled steroid dose (MD 77 μg beclomethasone equiv./day, 95% CI 69 to 84, 2 RCTs, 2554 participants, moderate-certainty evidence). FABA/ICS as required versus regular ICS plus FABA as required There may be little or no difference in the number of people with asthma exacerbations requiring systemic steroid with FABA/ICS as required compared with regular ICS (OR 0.79, 95% CI 0.59 to 1.07, 4 RCTs, 8065 participants, low-certainty evidence), equivalent to 81 people out of 1000 in the regular ICS plus FABA group experiencing an exacerbation requiring systemic steroids, compared to 65 (95% CI 49 to 86) out of 1000 FABA/ICS as required group. The odds of an asthma-related hospital admission or emergency department or urgent care visit may be reduced in those taking FABA/ICS as required (OR 0.63, 95% CI 0.44 to 0.91, 4 RCTs, 8065 participants, low-certainty evidence). Compared with regular ICS, any changes in asthma control, spirometry, peak flow rates (PFR), or asthma-associated quality of life, though favouring regular ICS, were small and less than the minimal clinically important differences (MCID). Adverse events, serious adverse events, total systemic corticosteroid dose and mortality were similar between groups, although deaths were rare, so confidence intervals for this analysis were wide. We found moderate-certainty evidence from four trials involving 7180 participants that FABA/ICS as required was likely associated with less average daily exposure to inhaled corticosteroids than those on regular ICS (MD -154.51 μg/day, 95% CI -207.94 to -101.09).

AUTHORS' CONCLUSIONS

We found FABA/ICS as required is clinically effective in adults and adolescents with mild asthma. Their use instead of FABA as required alone reduced exacerbations, hospital admissions or unscheduled healthcare visits and exposure to systemic corticosteroids and probably reduces adverse events. FABA/ICS as required is as effective as regular ICS and reduced asthma-related hospital admissions or unscheduled healthcare visits, and average exposure to ICS, and is unlikely to be associated with an increase in adverse events. Further research is needed to explore use of FABA/ICS as required in children under 12 years of age, use of other FABA/ICS preparations, and long-term outcomes beyond 52 weeks.

Machine learning reduced workload with minimal risk of missing studies: development and evaluation of a randomized controlled trial classifier for Cochrane Reviews

OBJECTIVES

This study developed, calibrated, and evaluated a machine learning classifier designed to reduce study identification workload in Cochrane for producing systematic reviews.

METHODS

A machine learning classifier for retrieving randomized controlled trials (RCTs) was developed (the "Cochrane RCT Classifier"), with the algorithm trained using a data set of title-abstract records from Embase, manually labeled by the Cochrane Crowd. The classifier was then calibrated using a further data set of similar records manually labeled by the Clinical Hedges team, aiming for 99% recall. Finally, the recall of the calibrated classifier was evaluated using records of RCTs included in Cochrane Reviews that had abstracts of sufficient length to allow machine classification.

RESULTS

The Cochrane RCT Classifier was trained using 280,620 records (20,454 of which reported RCTs). A classification threshold was set using 49,025 calibration records (1,587 of which reported RCTs), and our bootstrap validation found the classifier had recall of 0.99 (95% confidence interval 0.98-0.99) and precision of 0.08 (95% confidence interval 0.06-0.12) in this data set. The final, calibrated RCT classifier correctly retrieved 43,783 (99.5%) of 44,007 RCTs included in Cochrane Reviews but missed 224 (0.5%). Older records were more likely to be missed than those more recently published.

CONCLUSIONS

The Cochrane RCT Classifier can reduce manual study identification workload for Cochrane Reviews, with a very low and acceptable risk of missing eligible RCTs. This classifier now forms part of the Evidence Pipeline, an integrated workflow deployed within Cochrane to help improve the efficiency of the study identification processes that support systematic review production.

Systemic opioid regimens for postoperative pain in neonates

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To determine the effects of different regimens of systemic opioid analgesics in neonates (term or preterm) undergoing surgery, on mortality, pain and major neurodevelopmental disability. These different regimens may include: different doses of the same opioid; different routes of administration of the same opioid; continuous infusion versus bolus administration; or 'as needed' administration versus 'as scheduled' administration.

Prophylaxis against covid-19: living systematic review and network meta-analysis

UPDATES

This is the second version (first update) of the living systematic review, replacing the previous version (available as a data supplement). When citing this paper please consider adding the version number and date of access for clarity.

OBJECTIVE

To determine and compare the effects of drug prophylaxis on severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (covid-19).

DESIGN

Living systematic review and network meta-analysis (NMA).

DATA SOURCES

World Health Organization covid-19 database, a comprehensive multilingual source of global covid-19 literature to 4 March 2022.

STUDY SELECTION

Randomised trials in which people at risk of covid-19 were allocated to prophylaxis or no prophylaxis (standard care or placebo). Pairs of reviewers independently screened potentially eligible articles.

METHODS

After duplicate data abstraction, we conducted random-effects bayesian network meta-analysis. We assessed risk of bias of the included studies using a modification of the Cochrane risk of bias 2.0 tool and assessed the certainty of the evidence using the grading of recommendations assessment, development and evaluation (GRADE) approach.

RESULTS

The second iteration of this living NMA includes 32 randomised trials which enrolled 25 147 participants and addressed 21 different prophylactic drugs; adding 21 trials (66%), 18 162 participants (75%) and 16 (76%) prophylactic drugs. Of the 16 prophylactic drugs analysed, none provided convincing evidence of a reduction in the risk of laboratory confirmed SARS-CoV-2 infection. For admission to hospital and mortality outcomes, no prophylactic drug proved different than standard care or placebo. Hydroxychloroquine and vitamin C combined with zinc probably increase the risk of adverse effects leading to drug discontinuation—risk difference for hydroxychloroquine (RD) 6 more per 1000 (95% credible interval (CrI) 2 more to 10 more); for vitamin C combined with zinc, RD 69 more per 1000 (47 more to 90 more), moderate certainty evidence.

CONCLUSIONS

Much of the evidence remains very low certainty and we therefore anticipate future studies evaluating drugs for prophylaxis may change the results for SARS-CoV-2 infection, admission to hospital and mortality outcomes. Both hydroxychloroquine and vitamin C combined with zinc probably increase adverse effects.

SYSTEMATIC REVIEW REGISTRATION

This review was not registered. The protocol established a priori is included as a supplement.

FUNDING

This study was supported by the Canadian Institutes of Health Research (grant CIHR-IRSC:0579001321).

Crowdsourcing citation-screening in a mixed-studies systematic review: a feasibility study

BACKGROUND

Crowdsourcing engages the help of large numbers of people in tasks, activities or projects, usually via the internet. One application of crowdsourcing is the screening of citations for inclusion in a systematic review. There is evidence that a 'Crowd' of non-specialists can reliably identify quantitative studies, such as randomized controlled trials, through the assessment of study titles and abstracts. In this feasibility study, we investigated crowd performance of an online, topic-based citation-screening task, assessing titles and abstracts for inclusion in a single mixed-studies systematic review.

METHODS

This study was embedded within a mixed studies systematic review of maternity care, exploring the effects of training healthcare professionals in intrapartum cardiotocography. Citation-screening was undertaken via Cochrane Crowd, an online citizen science platform enabling volunteers to contribute to a range of tasks identifying evidence in health and healthcare. Contributors were recruited from users registered with Cochrane Crowd. Following completion of task-specific online training, the crowd and the review team independently screened 9546 titles and abstracts. The screening task was subsequently repeated with a new crowd following minor changes to the crowd agreement algorithm based on findings from the first screening task. We assessed the crowd decisions against the review team categorizations (the 'gold standard'), measuring sensitivity, specificity, time and task engagement.

RESULTS

Seventy-eight crowd contributors completed the first screening task. Sensitivity (the crowd's ability to correctly identify studies included within the review) was 84% (N = 42/50), and specificity (the crowd's ability to correctly identify excluded studies) was 99% (N = 9373/9493). Task completion was 33 h for the crowd and 410 h for the review team; mean time to classify each record was 6.06 s for each crowd participant and 3.96 s for review team members. Replicating this task with 85 new contributors and an altered agreement algorithm found 94% sensitivity (N = 48/50) and 98% specificity (N = 9348/9493). Contributors reported positive experiences of the task.

CONCLUSION

It might be feasible to recruit and train a crowd to accurately perform topic-based citation-screening for mixed studies systematic reviews, though resource expended on the necessary customised training required should be factored in. In the face of long review production times, crowd screening may enable a more time-efficient conduct of reviews, with minimal reduction of citation-screening accuracy, but further research is needed.

Regular treatment with formoterol and an inhaled corticosteroid versus regular treatment with salmeterol and an inhaled corticosteroid for chronic asthma: serious adverse events

BACKGROUND

Asthma is characterised by chronic inflammation of the airways and recurrent exacerbations with wheezing, chest tightness, and cough. Treatment with inhaled steroids and bronchodilators can result in good control of symptoms, prevention of further morbidity, and improved quality of life. However, an increase in serious adverse events with the use of both regular formoterol and regular salmeterol (long-acting beta₂-agonists) compared with placebo for chronic asthma has been demonstrated in previous Cochrane Reviews. This increase was statistically significant in trials that did not randomise participants to an inhaled corticosteroid, but not when formoterol or salmeterol was combined with an inhaled corticosteroid. The confidence intervals were found to be too wide to ensure that the addition of an inhaled corticosteroid renders regular long-acting beta₂-agonists completely safe; few participants and insufficient serious adverse events in these trials precluded a definitive decision about the safety of combination treatments.

OBJECTIVES

To assess risks of mortality and non-fatal serious adverse events in trials that have randomised patients with chronic asthma to regular formoterol and an inhaled corticosteroid versus regular salmeterol and an inhaled corticosteroid.

SEARCH METHODS

We searched the Cochrane Airways Register of Trials, CENTRAL, MEDLINE, Embase, and two trial registries to identify reports of randomised trials for inclusion. We checked manufacturers' websites and clinical trial registers for unpublished trial data, as well as Food and Drug Administration (FDA) submissions in relation to formoterol and salmeterol. The date of the most recent search was  24 February 2021.

SELECTION CRITERIA

We included controlled clinical trials with a parallel design, recruiting patients of any age and severity of asthma, if they randomised patients to treatment with regular formoterol versus regular salmeterol (each with a randomised inhaled corticosteroid) and were of at least 12 weeks' duration.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion in the review, extracted outcome data from published papers and trial registries, and applied GRADE rating for the results. We sought unpublished data on mortality and serious adverse events from study sponsors and authors. The primary outcomes were all cause mortality and non-fatal serious adverse events. We chose not to calculate an average result from all the formulations of formoterol and inhaled steroid, as the doses and delivery devices are too diverse to assume a single class effect.

MAIN RESULTS

Twenty-one studies in 11,572 adults and adolescents and two studies in 723 children met the eligibility criteria of the review. No data were available for two studies; therefore these were not included in the analysis. Among adult and adolescent studies, seven compared formoterol and budesonide to salmeterol and fluticasone (N = 7764), six compared formoterol and beclomethasone to salmeterol and fluticasone (N = 1923), two compared formoterol and mometasone to salmeterol and fluticasone (N = 1126), two compared formoterol and fluticasone to salmeterol and fluticasone (N = 790), and one compared formoterol and budesonide to salmeterol and budesonide (N = 229). In total, five deaths were reported among adults, none of which was thought to be related to asthma. The certainty of evidence for all-cause mortality was low, as there were not enough deaths to permit any precise conclusions regarding the risk of mortality on combination formoterol versus combination salmeterol. In all, 201 adults reported non-fatal serious adverse events. In studies comparing formoterol and budesonide to salmeterol and fluticasone, there were 77 in the formoterol arm and 68 in the salmeterol arm (Peto odds ratio (OR) 1.14, 95% confidence interval (CI) 0.82 to 1.59; 5935 participants, 7 studies; moderate-certainty evidence). In the formoterol and beclomethasone studies, there were 12 adults in the formoterol arm and 13 in the salmeterol arm with events (Peto OR 0.94, 95% CI 0.43 to 2.08; 1941 participants, 6 studies; moderate-certainty evidence). In the formoterol and mometasone studies, there were 18 in the formoterol arm and 11 in the salmeterol arm (Peto OR 1.02, 95% CI 0.47 to 2.20; 1126 participants, 2 studies; moderate-certainty evidence). One adult in the formoterol and fluticasone studies in the salmeterol arm experienced an event (Peto OR 0.05, 95% CI 0.00 to 3.10; 293 participants, 2 studies; low-certainty evidence). Another adult in the formoterol and budesonide compared to salmeterol and budesonide study in the formoterol arm had an event (Peto OR 7.45, 95% CI 0.15 to 375.68; 229 participants, 1 study; low-certainty evidence). Only 46 adults were reported to have experienced asthma-related serious adverse events. The certainty of the evidence was low to very low due to the small number of events and the absence of independent assessment of causation. The two studies in children compared formoterol and fluticasone to salmeterol and fluticasone. No deaths and no asthma-related serious adverse events were reported in these studies. Four all-cause serious adverse events were reported: three in the formoterol arm, and one in the salmeterol arm (Peto OR 2.72, 95% CI 0.38 to 19.46; 548 participants, 2 studies; low-certainty evidence).

AUTHORS' CONCLUSIONS

Overall, for both adults and children, evidence is insufficient to show whether regular formoterol in combination with budesonide, beclomethasone, fluticasone, or mometasone has a different safety profile from salmeterol in combination with fluticasone or budesonide. Five deaths of any cause were reported across all studies and no deaths from asthma; this information is insufficient to permit any firm conclusions about the relative risks of mortality on combination formoterol in comparison to combination salmeterol inhalers. Evidence on all-cause non-fatal serious adverse events indicates that there is probably little to no difference between formoterol/budesonide and salmeterol/fluticasone inhalers. However events for the other formoterol combination inhalers were too few to allow conclusions. Only 46 non-fatal serious adverse events were thought to be asthma related; this small number in addition to the absence of independent outcome assessment means that we have very low confidence for this outcome. We found no evidence of safety issues that would affect the choice between salmeterol and formoterol combination inhalers used for regular maintenance therapy by adults and children with asthma.

Exercise training for bronchiectasis

BACKGROUND

Bronchiectasis is characterised by excessive sputum production, chronic cough, and acute exacerbations and is associated with symptoms of dyspnoea and fatigue, which reduce exercise tolerance and impair quality of life. Exercise training in isolation or in conjunction with other interventions is beneficial for people with other respiratory diseases, but its effects in bronchiectasis have not been well established.

OBJECTIVES

To determine effects of exercise training compared to usual care on exercise tolerance (primary outcome), quality of life (primary outcome), incidence of acute exacerbation and hospitalisation, respiratory and mental health symptoms, physical function, mortality, and adverse events in people with stable or acute exacerbation of bronchiectasis.

SEARCH METHODS

We identified trials from the Cochrane Airways Specialised Register, ClinicalTrials.gov, and the World Health Organization trials portal, from their inception to October 2020. We reviewed respiratory conference abstracts and reference lists of all primary studies and review articles for additional references.

SELECTION CRITERIA

We included randomised controlled trials in which exercise training of at least four weeks' duration (or eight sessions) was compared to usual care for people with stable bronchiectasis or experiencing an acute exacerbation. Co-interventions with exercise training including education, respiratory muscle training, and airway clearance therapy were permitted if also applied as part of usual care.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and selected trials for inclusion, extracted outcome data, and assessed risk of bias. We contacted study authors for missing data. We calculated mean differences (MDs) using a random-effects model. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included six studies, two of which were published as abstracts, with a total of 275 participants. Five studies were undertaken with people with clinically stable bronchiectasis, and one pilot study was undertaken post acute exacerbation. All studies included co-interventions such as instructions for airway clearance therapy and/or breathing strategies, provision of an educational booklet, and delivery of educational sessions. The duration of training ranged from six to eight weeks, with a mix of supervised and unsupervised sessions conducted in the outpatient or home setting. No studies of children were included in the review; however we identified two studies as currently ongoing. No data were available regarding physical activity levels or adverse events. For people with stable bronchiectasis, evidence suggests that exercise training compared to usual care improves functional exercise tolerance as measured by the incremental shuttle walk distance, with a mean difference (MD) between groups of 87 metres (95% confidence interval (CI) 43 to 132 metres; 4 studies, 161 participants; low-certainty evidence). Evidence also suggests that exercise training improves six-minute walk distance (6MWD) (MD between groups of 42 metres, 95% CI 22 to 62; 1 study, 76 participants; low-certainty evidence). The magnitude of these observed mean changes appears clinically relevant as they exceed minimal clinically important difference (MCID) thresholds for people with chronic lung disease. Evidence suggests that quality of life improves following exercise training according to St George's Respiratory Questionnaire (SGRQ) total score (MD -9.62 points, 95% CI -15.67 to -3.56 points; 3 studies, 160 participants; low-certainty evidence), which exceeds the MCID of 4 points for this outcome. A reduction in dyspnoea (MD 1.0 points, 95% CI 0.47 to 1.53; 1 study, 76 participants) and fatigue (MD 1.51 points, 95% CI 0.80 to 2.22 points; 1 study, 76 participants) was observed following exercise training according to these domains of the Chronic Respiratory Disease Questionnaire. However, there was no change in cough-related quality of life as measured by the Leicester Cough Questionnaire (LCQ) (MD -0.09 points, 95% CI -0.98 to 0.80 points; 2 studies, 103 participants; moderate-certainty evidence), nor in anxiety or depression. Two studies reported longer-term outcomes up to 12 months after intervention completion; however exercise training did not appear to improve exercise capacity or quality of life more than usual care. Exercise training reduced the number of acute exacerbations of bronchiectasis over 12 months in people with stable bronchiectasis (odds ratio 0.26, 95% CI 0.08 to 0.81; 1 study, 55 participants). After an acute exacerbation of bronchiectasis, data from a single study (N = 27) suggest that exercise training compared to usual care confers little to no effect on exercise capacity (MD 11 metres, 95% CI -27 to 49 metres; low-certainty evidence), SGRQ total score (MD 6.34 points, 95%CI -17.08 to 29.76 points), or LCQ score (MD -0.08 points, 95% CI -0.94 to 0.78 points; low-certainty evidence) and does not reduce the time to first exacerbation (hazard ratio 0.83, 95% CI 0.31 to 2.22).

AUTHORS' CONCLUSIONS

This review provides low-certainty evidence suggesting improvement in functional exercise capacity and quality of life immediately following exercise training in people with stable bronchiectasis; however the effects of exercise training on cough-related quality of life and psychological symptoms appear to be minimal. Due to inadequate reporting of methods, small study numbers, and variation between study findings, evidence is of very low to moderate certainty. Limited evidence is available to show longer-term effects of exercise training on these outcomes.

A Living, Interactive Systematic Review and Network Meta-analysis of First-line Treatment of Metastatic Renal Cell Carcinoma

CONTEXT

Identifying the most effective first-line treatment for metastatic renal cell carcinoma (mRCC) is challenging as rapidly evolving data quickly outdate the existing body of evidence, and current approaches to presenting the evidence in user-friendly formats are fraught with limitations.

OBJECTIVE

To maintain living evidence for contemporary first-line treatment for previously untreated mRCC.

EVIDENCE ACQUISITION

We have created a living, interactive systematic review (LISR) and network meta-analysis for first-line treatment of mRCC using data from randomized controlled trials comparing contemporary treatment options with single-agent tyrosine kinase inhibitors. We applied an advanced programming and artificial intelligence-assisted framework for evidence synthesis to create a living search strategy, facilitate screening and data extraction using a graphical user interface, automate the frequentist network meta-analysis, and display results in an interactive manner.

EVIDENCE SYNTHESIS

As of October 22, 2020, the LISR includes data from 14 clinical trials. Baseline characteristics are summarized in an interactive table. The cabozantinib + nivolumab combination (CaboNivo) is ranked the highest for the overall response rate, progression-free survival, and overall survival, whereas ipilimumab + nivolumab (NivoIpi) is ranked the highest for achieving a complete response (CR). NivoIpi, and atezolizumab + bevacizumab (AteBev) were ranked highest (lowest toxicity) and CaboNivo ranked lowest for treatment-related adverse events (AEs). Network meta-analysis results are summarized as interactive tables and plots, GRADE summary-of-findings tables, and evidence maps.

CONCLUSIONS

This innovative living and interactive review provides the best current evidence on the comparative effectiveness of multiple treatment options for patients with untreated mRCC. Trial-level comparisons suggest that CaboNivo is likely to cause more AEs but is ranked best for all efficacy outcomes, except NivoIpi offers the best chance of CR. Pembrolizumab + axitinib and NivoIpi are acceptable alternatives, except NivoIpi may not be preferred for patients with favorable risk. Although network meta-analysis provides rankings with statistical adjustments, there are inherent biases in cross-trial comparisons with sparse direct evidence that does not replace randomized comparisons.

PATIENT SUMMARY

It is challenging to decide the best option among the several treatment combinations of immunotherapy and targeted treatments for newly diagnosed metastatic kidney cancer. We have created interactive evidence summaries of multiple treatment options that present the benefits and harms and evidence certainty for patient-important outcomes. This evidence is updated as soon as new studies are published.

The decisions and processes involved in a systematic search strategy: a hierarchical framework

OBJECTIVE

The decisions and processes that may compose a systematic search strategy have not been formally identified and categorized. This study aimed to (1) identify all decisions that could be made and processes that could be used in a systematic search strategy and (2) create a hierarchical framework of those decisions and processes.

METHODS

The literature was searched for documents or guides on conducting a literature search for a systematic review or other evidence synthesis. The decisions or processes for locating studies were extracted from eligible documents and categorized into a structured hierarchical framework. Feedback from experts was sought to revise the framework. The framework was revised iteratively and tested using recently published literature on systematic searching.

RESULTS

Guidance documents were identified from expert organizations and a search of the literature and Internet. Data were extracted from 74 eligible documents to form the initial framework. The framework was revised based on feedback from 9 search experts and further review and testing by the authors. The hierarchical framework consists of 119 decisions or processes sorted into 17 categories and arranged under 5 topics. These topics are "Skill of the searcher," "Selecting information to identify," "Searching the literature electronically," "Other ways to identify studies," and "Updating the systematic review."

CONCLUSIONS

The work identifies and classifies the decisions and processes used in systematic searching. Future work can now focus on assessing and prioritizing research on the best methods for successfully identifying all eligible studies for a systematic review.

The PRISMA 2020 statement: An updated guideline for reporting systematic reviews

The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, published in 2009, was designed to help systematic reviewers transparently report why the review was done, what the authors did, and what they found. Over the past decade, advances in systematic review methodology and terminology have necessitated an update to the guideline. The PRISMA 2020 statement replaces the 2009 statement and includes new reporting guidance that reflects advances in methods to identify, select, appraise, and synthesise studies. The structure and presentation of the items have been modified to facilitate implementation. In this article, we present the PRISMA 2020 27-item checklist, an expanded checklist that details reporting recommendations for each item, the PRISMA 2020 abstract checklist, and the revised flow diagrams for original and updated reviews.