Simple randomization did not protect against bias in smaller trials

PROTOCOL: Key characteristics of effective preschool-based interventions to promote self-regulation: A systematic review and meta-analysis

This is the protocol for a Cochrane Review. The objectives are as follows: The aim of this systematic review is to advance our understanding of the key characteristics of effective preschool-based interventions designed to foster self-regulation. To accomplish this, the review addresses the following questions: 1. What types of preschool-based interventions have been developed to promote self-regulation? 2. What is the average effect of these preschool-based interventions on self-regulation, focusing on four key constructs: integrative effortful control, integrative executive function, self-regulation, and self-regulated learning? 3. What characteristics-such as Resource Allocation, Activity Type, and Instruction Method-could potentially contribute to the effects of preschool-based interventions in promoting self-regulation?

Choosing and evaluating randomisation methods in clinical trials: a qualitative study

BACKGROUND

There exist many different methods of allocating participants to treatment groups during a randomised controlled trial. Although there is research that explores trial characteristics that are associated with the choice of method, there is still a lot of variety in practice not explained. This study used qualitative methods to explore more deeply the motivations behind researchers' choice of randomisation, and which features of the method they use to evaluate the performance of these methods.

METHODS

Data was collected from online focus groups with various stakeholders involved in the randomisation process. Focus groups were recorded and then transcribed verbatim. A thematic analysis was used to analyse the transcripts.

RESULTS

Twenty-five participants from twenty clinical trials units across the UK were recruited to take part in one of four focus groups. Four main themes were identified: how randomisation methods are selected; researchers' opinions of the different methods; which features of the method are desirable and ways to measure method features. Most researchers agree that the randomisation method should be selected based on key trial characteristics; however, for many, a unit standard is in place. Opinions of methods were varied with some participants favouring stratified blocks and others favouring minimisation. This was generally due to researchers' perception of the effect these methods had on balance and predictability. Generally, predictability was considered more important than balance as adjustments cannot be made for it; however, most researchers felt that the importance of these two methods was dependent on the design of the study. Balance is usually evaluated by tabulating variables by treatment arm and looking for perceived imbalances, predictability was generally considered much harder to measure, partly due to differing definitions.

CONCLUSION

There is a wide variety in practice on how randomisation methods are selected and researcher's opinions on methods. The difference in practice observed when looking at randomisation method selection can be explained by a difference in unit practice, and also by a difference in researchers prioritisation of balance and predictability. The findings of this study show a need for more guidance on randomisation method selection.

Systematic heterogenization revisited: Increasing variation in animal experiments to improve reproducibility?

Life sciences are currently facing a reproducibility crisis. Originally, the crisis was born out of single alarming failures to reproduce findings at different times and locations. Nowadays, systematic studies indicate that the prevalence of irreproducible research does in fact exceed 50%. Viewed from a rather cynical perspective, Fett's law of the lab "Never replicate a successful experiment" has thus taken on a completely new meaning. In this respect, animal research has come under particular scrutiny, as the stakes are high in terms of both research ethics and societal impact. To counteract this, it is essential to identify sources of poor reproducibility as well as to iron out these failures. We here review the current debate, briefly discuss potential reasons, and summarize steps that have already been undertaken to improve reproducibility in animal research. By the example of classical behavioural phenotyping studies, we particularly highlight the role strict standardization plays in exacerbating the crisis, and review the concept of systematic heterogenization as an alternative strategy to deal with variation in animal studies. Briefly, we argue that systematic variation rather than strict homogenization of experimental conditions benefits the robustness of research findings, and hence their reproducibility. To this end, we will present concrete examples for systematically heterogenized experiments and provide a practical guide on how to apply systematic heterogenization in experimental practice.

Drawing causal inferences from randomized controlled trials in psychotherapy research

OBJECTIVE

Randomized control trials (RCTs) have played a critical role in psychotherapy research. This article discusses RCTs in the context of the criteria for drawing causal inferences in psychotherapy and intervention research more generally. The article also highlights underused variations of RCTs and how they not only establish causal relations but also address critical questions that can improve our intervention portfolio and patient care.

CONCLUSION

Random assignment is discussed in terms of what it can and cannot do in relation to drawing conclusions about the effects of interventions. Finally, RCTs are examined in the context of multiple questions that can guide therapy research, improve patient care, and develop treatments that reach people in need of psychological services.

Observed intervention effects for mortality in randomised clinical trials: a methodological study protocol

INTRODUCTION

It is essential to choose a realistic anticipated intervention effect when calculating a sample size for a randomised clinical trial. Unfortunately, anticipated intervention effects are often inflated, when compared with the 'true' intervention effects. This is documented for mortality in critical care trials. A similar pattern might exist across different medical specialties. This study aims to estimate the range of observed intervention effects for all-cause mortality in trials included in Cochrane Reviews, within each Cochrane Review Group.

METHODS AND ANALYSIS

We will include randomised clinical trials assessing all-cause mortality as an outcome. Trials will be identified from Cochrane Reviews published in the Cochrane Database of Systematic Reviews. Cochrane Reviews will be clustered according to the registered Cochrane Review Group (eg, Anaesthesia, Emergency and Critical Care) and the statistical analyses will be conducted for each Cochrane Review Group and overall. The median relative risk and IQR for all-cause mortality and the proportion of trials with a relative all-cause mortality risk within seven different ranges will be reported (relative risk below 0.70, 0.70-0.79, 0.80-0.89, 0.90-1.09, 1.10-1.19, 1.20-1.30 and above 1.30). Subgroup analyses will explore the effects of original design, sample size, risk of bias, disease, intervention type, follow-up length, participating centres, funding type, information size and outcome hierarchy.

ETHICS AND DISSEMINATION

Since we will use summary data from trials already approved by relevant ethical committees, this study does not require ethical approval. Regardless of our findings, the results will be published in an international peer-reviewed journal.

The fragility of significant results from randomized controlled trials in esophageal surgeries

While randomized controlled trials (RCTs) are regarded as one of the highest forms of clinical research, the robustness of their P values can be difficult to ascertain. Defined as the minimum number of patients in a study arm that would need to be changed from a non-event to event for the findings to lose significance, the Fragility Index is a method for evaluating results from these trials. This study aims to calculate the Fragility Index for trials evaluating perioperative esophagectomy-related interventions to determine the strength of RCTs in this field. MEDLINE and EMBASE were searched for RCTs related to esophagectomy that reported a significant dichotomous outcome. Two reviewers independently screened articles and performed the data extractions with risk of bias assessment. The Fragility Index was calculated using a two-tailed Fisher's exact test. Bivariate correlation was conducted to evaluate associations between the Fragility Index and study characteristics. 41 RCTs were included, and the median sample size was 80 patients [Interquartile range (IQR) 60-161]. Of the included outcomes, 29 (71%) were primary, and 12 (29%) were secondary. The median Fragility Index was 1 (IQR 1-3), meaning that by changing one patient from a non-event to event, the results would become non-significant. Fragility Index was correlated with P value, number of events, and journal impact factor. The RCTs related to esophagectomy did not prove to be robust, as the significance of their results could be changed by altering the outcome status of a handful of patients in one study arm.

Balancing after randomization in orthopedic trials: Are we even or even paying attention?

A cornerstone of evidence-based medicine is the randomized controlled trial (RCT). While randomization seeks to balance study groups on potential confounders, this is not always achieved. Especially in orthopedic research where RCTs are often of modest size, imbalances can exist and may be a significant issue. We sought to describe whether orthopedic RCTs assess balancing between study groups, use statistical hypothesis testing to compare baseline characteristics between groups, and have balanced baseline characteristics between groups. All RCTs from four leading orthopedic journals published between July 2019 and June 2020 were identified and those reporting original trial results reviewed for discussion of balancing, use of statistical significance testing to compare baseline characteristics, and patient reported outcome measures (PROMs) at baseline. Standardized mean differences of baseline PROMs were calculated to assess balancing. Of 86 orthopedic RCTs reviewed, 59 (69%) assessed balancing and 50 (58%) used statistical significance testing to compare baseline characteristics. Of 74 articles specifying a primary outcome, 33 (45%) used a PROM with 23 (70%) reporting baseline PROM values. Of these articles, 17 (74%) had a difference of less than 0.25 standard deviations (SDs) between groups, 4 (17%) had a difference of between 0.25 and 0.50 SDs, and 3 (13%) had a difference greater than 0.5 SDs. Orthopedic RCTs usually assess balancing after randomization though there is room for improvement with over half of articles using hypothesis testing to assess baseline differences as opposed to a measure of the magnitude of the difference.

The effect of levocarnitine supplementation on dialysis-related hypotension: A systematic review, meta-analysis, and trial sequential analysis

BACKGROUND

Dialysis patients have been shown to have low serum carnitine due to poor nutrition, deprivation of endogenous synthesis from kidneys, and removal by hemodialysis. Carnitine deficiency leads to impaired cardiac function and dialysis-related hypotension which are associated with increased mortality. Supplementing with levocarnitine among hemodialysis patients may diminish incidence of intradialytic hypotension. Data on this topic, however, lacks consensus.

METHODS

We conducted electronic searches in PubMed, Embase and Cochrane Central Register of Controlled Trials from January 1960 to 19th November 2021 to identify randomized controlled studies (RCTs), which examined the effects of oral or intravenous levocarnitine (L-carnitine) on dialysis-related hypotension among hemodialysis patients. The secondary outcome was muscle cramps. Study results were pooled and analyzed utilizing the random-effects model. Trial sequential analysis (TSA) was performed to assess the strength of current evidence.

RESULTS

Eight trials with 224 participants were included in our meta-analysis. Compared to control group, L-carnitine reduced the incidence of dialysis-related hypotension among hemodialysis patients (pooled OR = 0.26, 95% CI [0.10-0.72], p = 0.01, I2 = 76.0%). TSA demonstrated that the evidence was sufficient to conclude the finding. Five studies with 147 participants showed a reduction in the incidence of muscle cramps with L-carnitine group (pooled OR = 0.22, 95% CI [0.06-0.81], p = 0.02, I2 = 74.7%). However, TSA suggested that further high-quality studies were required. Subgroup analysis on the route of supplementation revealed that only oral but not intravenous L-carnitine significantly reduced dialysis-related hypotension. Regarding dose and duration of L-carnitine supplementation, the dose > 4,200 mg/week and duration of at least 12 weeks appeared to prevent dialysis-related hypotension.

CONCLUSION

Supplementing oral L-carnitine for at least three months above 4,200 mg/week helps prevent dialysis-related hypotension. L-carnitine supplementation may ameliorate muscle cramps. Further well-powered studies are required to conclude this benefit.

Systematic reviews do not (yet) represent the 'gold standard' of evidence: A position paper

The low quality of included trials, insufficient rigour in review methodology, ignorance of key pain issues, small size, and over-optimistic judgements about the direction and magnitude of treatment effects all devalue systematic reviews, supposedly the 'gold standard' of evidence. Available evidence indicates that almost all systematic reviews in the published literature contain fatal flaws likely to make their conclusions incorrect and misleading. Only 3 in every 100 systematic reviews are deemed to have adequate methods and be clinically useful. Examples of research waste and questionable ethical standards abound: most trials have little hope of providing useful results, and systematic review of hopeless trials inspires no confidence. We argue that results of most systematic reviews should be dismissed. Forensically critical systematic reviews are essential tools to improve the quality of trials and should be encouraged and protected.

Anterior versus posterior entry site for ventriculoperitoneal shunt insertion: a randomized controlled trial by the Hydrocephalus Clinical Research Network

OBJECTIVE

The primary objective of this trial was to determine if shunt entry site affects the risk of shunt failure.

METHODS

The authors performed a parallel-design randomized controlled trial with an equal allocation of patients who received shunt placement via the anterior entry site and patients who received shunt placement via the posterior entry site. All patients were children with symptoms or signs of hydrocephalus and ventriculomegaly. Patients were ineligible if they had a prior history of shunt insertion. Patients received a ventriculoperitoneal shunt after randomization; randomization was stratified by surgeon. The primary outcome was shunt failure. The planned minimum follow-up was 18 months. The trial was designed to achieve high power to detect a 10% or greater absolute difference in the shunt failure rate at 1 year. An independent, blinded adjudication committee determined eligibility and the primary outcome. The study was conducted by the Hydrocephalus Clinical Research Network.

RESULTS

The study randomized 467 pediatric patients at 14 tertiary care pediatric hospitals in North America from April 2015 to January 2019. The adjudication committee, blinded to intervention, excluded 7 patients in each group for not meeting the study inclusion criteria. For the primary analysis, there were 229 patients in the posterior group and 224 patients in the anterior group. The median patient age was 1.3 months, and the most common etiologies of hydrocephalus were postintraventricular hemorrhage secondary to prematurity (32.7%), myelomeningocele (16.8%), and aqueductal stenosis (10.8%). There was no significant difference in the time to shunt failure between the entry sites (log-rank test, stratified by age < 6 months and ≥ 6 months; p = 0.061). The hazard ratio (HR) of a posterior shunt relative to an anterior shunt was calculated using a univariable Cox regression model and was nonsignificant (HR 1.35, 95% CI, 0.98-1.85; p = 0.062). No significant difference was found between entry sites for the surgery duration, number of ventricular catheter passes, ventricular catheter location, and hospital length of stay. There were no significant differences between entry sites for intraoperative complications, postoperative CSF leaks, pseudomeningoceles, shunt infections, skull fractures, postoperative seizures, new-onset epilepsy, or intracranial hemorrhages.

CONCLUSIONS

This randomized controlled trial comparing the anterior and posterior shunt entry sites has demonstrated no significant difference in the time to shunt failure. Anterior and posterior entry site surgeries were found to have similar outcomes and similar complication rates.

When randomisation is not good enough: Matching groups in intervention studies

Randomised assignment of individuals to treatment and controls groups is often considered the gold standard to draw valid conclusions about the efficacy of an intervention. In practice, randomisation can lead to accidental differences due to chance. Researchers have offered alternatives to reduce such differences, but these methods are not used frequently due to the requirement of advanced statistical methods. Here, we recommend a simple assignment procedure based on variance minimisation (VM), which assigns incoming participants automatically to the condition that minimises differences between groups in relevant measures. As an example of its application in the research context, we simulated an intervention study whereby a researcher used the VM procedure on a covariate to assign participants to a control and intervention group rather than controlling for the covariate at the analysis stage. Among other features of the simulated study, such as effect size and sample size, we manipulated the correlation between the matching covariate and the outcome variable and the presence of imbalance between groups in the covariate. Our results highlighted the advantages of VM over prevalent random assignment procedure in terms of reducing the Type I error rate and providing accurate estimates of the effect of the group on the outcome variable. The VM procedure is valuable in situations whereby the intervention to an individual begins before the recruitment of the entire sample size is completed. We provide an Excel spreadsheet, as well as scripts in R, MATLAB, and Python to ease and foster the implementation of the VM procedure.

Extended release injectable naltrexone before vs. after release: A randomized trial of opioid addicted persons who are in prison

BACKGROUND

Usual treatment for persons with opioid use disorders who are in prison is detoxification with referral to treatment after release but failure to engage in treatment and relapse is common. Starting medication treatment before release might improve outcomes.

OBJECTIVES

Determine if administering extended-release injectable naltrexone (XR-NTX) before release (BR) from prison results in less relapse within the first three months after release than when offered by referral after release (AR).

METHODS

The study randomized 1:1 persons who had an OUD, expressed interest in XR-NTX, and met study admission criteria to receive XR-NTX BR or at a local program AR, with continued medication and counseling available at that program.

RESULTS

Four-hundred and two persons expressed interest in the study, 222 consented, and the study randomized 146. Uncertainty about release dates resulted in a time lag between randomization and final disposition during which 60 of the randomized patients were sentenced to other facilities, withdrew consent, or became otherwise unavailable for study treatment, leaving 86 for outcome analyses (38, BR; 48 AR). Missed follow-up appointments on the remaining 86 led to development of a phone-based questionnaire to determine presence/absence of relapse. Using it to supplement other data, we were able to confirm relapse or nonrelapse for 63 of the 86 (73%). All BR and a third of the AR patients received their first XR-NTX dose, however dropout was high and nonrelapse by month three was not significantly different between BR (39.5%) and AR (25%) (Chisq (2) = 3.23, p = 0.20).

CONCLUSIONS

BR patients were much more likely to receive medication and its extended relapse and overdose protection effects in the first weeks after release. Dropout was high and the study detected no significant difference in relapse by month 3; however, the less-than-planned number of patients and missing data make this finding inconclusive.

Acceptability and Feasibility of Early Palliative Care Among Women with Advanced Epithelial Ovarian Cancer: A Randomized Controlled Pilot Study

OBJECTIVE

To evaluate the acceptability of early palliative care (EPC) among patients with advanced ovarian cancer and to determine the feasibility of larger-scale phase III trials.

METHODS

We performed a randomized controlled pilot study of adult women (>18 years) with pathologically confirmed epithelial ovarian cancer that had recurred or progressed on first-line therapy and had no immediate need for palliative care. We randomly assigned patients to either EPC or standard oncologic care (SOC), and collected patient-reported outcomes (PRO) at baseline, 3 months, and 6 months; end-of-life care quality indicators were collected at study completion. Study endpoints were rates of enrollment, EPC adherence, and PRO completion.

RESULTS

Of 32 eligible patients approached, 23 enrolled (72%; 95% CI 53-86) and were randomly assigned to either EPC (n = 12) or SOC (n = 11). At baseline, participants had poor physical and emotional wellbeing, high rates of depression (65%), and understood that their disease was not curable (87%). Eleven patients (92%; 95% CI 62-100) attended their EPC consultation, and all visits took place within 4 weeks of enrollment. However, PRO completion was low due to deaths by 3 (5/23) and 6 months (9/23).

CONCLUSION

Patients had accurate perceptions of their disease status, were willing to be randomly assigned to EPC, and attended scheduled appointments. However, a definitive trial in this group is not feasible without major adjustments to eligibility criteria and a multicentre, international effort. We propose that EPC be considered routinely at progression or recurrence given patients' symptom burden and clear acceptance of the intervention, as well as evidence of benefit from adequately powered trials in other malignancies.

Interventions for treating leg ulcers in people with sickle cell disease

BACKGROUND

The frequency of skin ulceration makes an important contributor to the morbidity burden in people with sickle cell disease. Many treatment options are available to the healthcare professional, although it is uncertain which treatments have been assessed for effectiveness in people with sickle cell disease. This is an update of a previously published Cochrane Review.

OBJECTIVES

To assess the clinical effectiveness and harms of interventions for treating leg ulcers in people with sickle cell disease.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register. We searched LILACS (1982 to January 2020), ISI Web of Knowledge (1985 to January 2020), and the Clinical Trials Search Portal of the World Health Organization (January 2020). We checked the reference lists of all the trials identified. We also contacted those groups or individuals who may have completed relevant randomised trials in this area. Date of the last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 13 January 2020; date of the last search of the Cochrane Wounds Group Trials Register: 17 February 2017.

SELECTION CRITERIA

Randomised controlled trials of interventions for treating leg ulcers in people with sickle cell disease compared to placebo or an alternative treatment.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion. All three authors independently assessed the risk of bias of the included studies and extracted data. We used GRADE to assess the quality of the evidence.

MAIN RESULTS

Six studies met the inclusion criteria (198 participants with 250 ulcers). Each trial investigated a different intervention and within this review we have grouped these as systemic pharmaceutical interventions (L-cartinine, arginine butyrate, isoxsuprine) and topical pharmaceutical interventions (Solcoseryl® cream, arginine-glycine-aspartic acid (RGD) peptide dressing and topical antibiotics). No trials on non-pharmaceutical interventions were included in the review. All trials had an overall unclear or high risk of bias, and drug companies sponsored four of them. We were unable to pool findings due to the heterogeneity in outcome definitions, and inconsistency between the units of randomisation and analysis. Three interventions reported on the change in ulcer size (arginine butyrate, RGD peptide, L-cartinine). Of these, only arginine butyrate showed a reduction of ulcer size compared with a control group, mean reduction -5.10 cm² (95% CI -9.65 to -0.55), but we are uncertain whether this reduces ulcer size compared to standard care alone as the certainty of the evidence has been assessed as very low. Three trials reported on complete leg ulcer closure (isoxsuprine, arginine butyrate, RGD peptide matrix; very low quality of evidence). None reported a clinical benefit. No trial reported on: the time to complete ulcer healing; ulcer-free survival following treatment for sickle cell leg ulcers; quality of life measures; incidence of amputation or harms.

AUTHORS' CONCLUSIONS

Given the very low quality of the evidence identified in this updated Cochrane Review we are uncertain whether any of the assessed pharmaceutical interventions reduce ulcer size or result in leg ulcer closure in treated participants compared to controls. However, this intervention was assessed as having a high risk of bias due to inadequacies in the single trial report. Other included studies were also assessed as having an unclear or high risk of bias. The harm profile of the all interventions remains inconclusive.

Using Trial Sequential Analysis for estimating the sample sizes of further trials: example using smoking cessation intervention

Background

Assessing benefits and harms of health interventions is resource-intensive and often requires feasibility and pilot trials followed by adequately powered randomised clinical trials. Data from feasibility and pilot trials are used to inform the design and sample size of the adequately powered randomised clinical trials. When a randomised clinical trial is conducted, results from feasibility and pilot trials may be disregarded in terms of benefits and harms.

Methods

We describe using feasibility and pilot trial data in the Trial Sequential Analysis software to estimate the required sample size for one or more trials investigating a behavioural smoking cessation intervention. We show how data from a new, planned trial can be combined with data from the earlier trials using trial sequential analysis methods to assess the intervention’s effects.

Results

We provide a worked example to illustrate how we successfully used the Trial Sequential Analysis software to arrive at a sensible sample size for a new randomised clinical trial and use it in the argumentation for research funds for the trial.

Conclusions

Trial Sequential Analysis can utilise data from feasibility and pilot trials as well as other trials, to estimate a sample size for one or more, similarly designed, future randomised clinical trials. As this method uses available data, estimated sample sizes may be smaller than they would have been using conventional sample size estimation methods.

Corticosteroids versus clobazam in epileptic encephalopathy with ESES: a European multicentre randomised controlled clinical trial (RESCUE ESES*)

BACKGROUND

Epileptic encephalopathy with electrical status epilepticus in sleep (ESES) is an epilepsy syndrome occurring almost exclusively in children, usually at an age between 4 and 12 years. It is characterised by abundant sleep-induced epileptic activity in the electroencephalogram (EEG) and by acquired cognitive and behavioural deficits. The goal of treatment is to prevent further decline or even improve cognitive functioning. Based on mostly small and retrospective studies, corticosteroids and clobazam are regarded by many clinicians as the most effective pharmacological treatments. This European multicentre randomised controlled trial is designed to compare the effects of corticosteroids and clobazam on cognitive functioning after 6 months. Secondary outcomes include cognitive functioning after 18 months, EEG abnormalities in sleep, safety and tolerability, and seizure frequency. We also aimed at investigating whether treatment response in epileptic encephalopathy with ESES can be predicted by measurement of inflammatory mediators and autoantibodies in serum.

METHODS

The pragmatic study will be performed in centres with expertise in the treatment of rare paediatric epilepsy syndromes across Europe. A total of 130 patients, 2 to 12 years of age, with epileptic encephalopathy with ESES will be enrolled and randomised in a 1:1 ratio to receive either corticosteroids (monthly intravenous methylprednisolone pulses or daily oral prednisolone) or oral clobazam for 6 months according to an open-label parallel-group design. Follow-up visits with clinical assessment, EEGs, and neuropsychological testing are scheduled for up to 18 months. Blood samples for cytokine and autoantibody testing are obtained before treatment and 8 months after treatment initiation.

DISCUSSION

The treatment of epileptic encephalopathy with ESES aims at improving cognitive outcome. This randomised controlled study will compare the most frequently used treatments, i.e. corticosteroids and clobazam. If the study proves superiority of one treatment over the other or identifies biomarkers of treatment response, results will guide clinicians in the early treatment of this severe epilepsy syndrome.

TRIAL REGISTRATION

ISRCTN, ISRCTN42686094 . Registered on 24 May 2013.

Incomparability of treatment groups is often blindly ignored in randomised controlled trials - a post hoc analysis of baseline characteristic tables

OBJECTIVES

Randomisation is often believed to lead to baseline comparability of treatment groups in controlled trials. This study aims to challenge this popular belief, which is relevant in expectation- but not necessarily in realisation.

STUDY DESIGN AND SETTING

After presenting an overview of methods for assessing baseline comparability of treatment groups in randomised controlled trials (RCTs), we reviewed RCTs published over 1 year in three high-impact medical journals. We extracted data regarding the methods used to evaluate baseline comparability. To quantify baseline balance, we calculated post hoc standardised mean differences (SMDs) in baseline characteristics reported in these trials.

RESULTS

Amongst 142 RCTs, 120 (84.5%) claimed that baseline comparability was achieved. However, 81 RCTs (57%) did not report how they assessed this balance. The rest (61 RCTs, 43%) used traditional statistical tests, which are deemed inappropriate for balance checking. Our post hoc calculation of SMDs showed that 49 (34.5%) RCTs had at least one baseline variable, which might have been strongly unbalanced (i.e., SMD ≥25%) across treatment groups.

CONCLUSION

Baseline incomparability of treatment groups in RCTs is often blindly ignored. We suggest it be thoroughly evaluated and transparently reported, using the standardised mean difference or other proper balance metrics.

Impact of oral preoperative and perioperative immunonutrition on postoperative infection and mortality in patients undergoing cancer surgery: systematic review and meta-analysis with trial sequential analysis

Background

Infectious complications occur in 4–22 per cent of patients undergoing surgical resection of malignant solid tumours. Improving the patient's immune system in relation to oncological surgery with immunonutrition may play an important role in reducing postoperative infections. A meta‐analysis was undertaken to evaluate the potential clinical benefits of immunonutrition on postoperative infections and 30‐day mortality in patients undergoing oncological surgery.

Methods

PubMed, Embase and Cochrane Library databases were searched to identify eligible studies.

Eligible studies had to include patients undergoing elective curative surgery for a solid malignant tumour and receiving immunonutrition orally before surgery, including patients who continued immunonutrition into the postoperative period. The main outcome was overall infectious complications; secondary outcomes were surgical‐site infection (SSI) and 30‐day mortality, described by relative risk (RR) with trial sequential analysis (TSA). Risk of bias was assessed according to Cochrane methodology.

Results

Some 22 RCTs with 2159 participants were eligible for meta‐analysis. Compared with the control group, immunonutrition reduced overall infectious complications (RR 0·58, 95 per cent c.i. 0·48 to 0·70; I² = 7 per cent; TSA‐adjusted 95 per cent c.i. 0·28 to 1·21) and SSI (RR 0·65, 95 per cent c.i. 0·50 to 0·85; I² = 0 per cent; TSA‐adjusted 95 per cent c.i. 0·21 to 2·04). Thirty‐day mortality was not altered by immunonutrition (RR 0·69, 0·33 to 1·40; I² = 0 per cent).

Conclusion

Immunonutrition reduced overall infectious complications, even after controlling for random error, and also reduced SSI. The quality of evidence was moderate, and mortality was not affected by immunonutrition (low quality). Oral immunonutrition merits consideration as a means of reducing overall infectious complications after cancer surgery.

Effect of a feedback system on the quality of 2-minute chest compression-only cardiopulmonary resuscitation: a randomised crossover simulation study

OBJECTIVE

We evaluated the quality of 2-minute continuous chest compressions (CCCs) performed by emergency staff in 30-second intervals to determine the effect of a feedback system on maintaining the quality of CCCs.

METHODS

Two hundred three physicians and nurses were randomised into two groups. Each participant performed 2-minute CCCs both with and without feedback. Group A performed CCCs under the guidance of a feedback device followed by performance without feedback, and Group B performed these tasks in reverse order. The primary outcome was the proportion of optimal compressions; i.e., compressions at both the correct rate (100-120 beats/minute) and correct depth (5-6 cm).

RESULTS

During 2-minute CCCs, the proportion of optimal compressions was poor in personnel without feedback. The proportion of optimal compressions was unchanged and low from 2.4% (interquartile range, 0.0%-32.8%) in the first 30 seconds to 3.3% (0.0%-47.7%) in the last 30 seconds of the 2-minute period. Use of the feedback device significantly improved and maintained the quality of compressions from the first 30 seconds (53.3%; 29.2%-70.4%) to the last 30 seconds (82.8%; 50.8%-96.2%).

CONCLUSION

Use of the feedback device was helpful for maintaining the quality of CCCs.

DEBATE-statistical analysis plans for observational studies

Background

All clinical research benefits from transparency and validity. Transparency and validity of studies may increase by prospective registration of protocols and by publication of statistical analysis plans (SAPs) before data have been accessed to discern data-driven analyses from pre-planned analyses.

Main message

Like clinical trials, recommendations for SAPs for observational studies increase the transparency and validity of findings. We appraised the applicability of recently developed guidelines for the content of SAPs for clinical trials to SAPs for observational studies. Of the 32 items recommended for a SAP for a clinical trial, 30 items (94%) were identically applicable to a SAP for our observational study. Power estimations and adjustments for multiplicity are equally important in observational studies and clinical trials as both types of studies usually address multiple hypotheses. Only two clinical trial items (6%) regarding issues of randomisation and definition of adherence to the intervention did not seem applicable to observational studies. We suggest to include one new item specifically applicable to observational studies to be addressed in a SAP, describing how adjustment for possible confounders will be handled in the analyses.

Conclusion

With only few amendments, the guidelines for SAP of a clinical trial can be applied to a SAP for an observational study. We suggest SAPs should be equally required for observational studies and clinical trials to increase their transparency and validity.

Antibiotic therapy for adults with neurosyphilis

BACKGROUND

Neurosyphilis is an infection of the central nervous system, caused by Treponema pallidum, a spirochete capable of infecting almost any organ or tissue in the body causing neurological complications due to the infection. This disease is a tertiary manifestation of syphilis. The first-line treatment for neurosyphilis is aqueous crystalline penicillin. However, in cases such as penicillin allergy, other regimes of antibiotic therapy can be used.

OBJECTIVES

To assess the clinical effectiveness and safety of antibiotic therapy for adults with neurosyphilis.

SEARCH METHODS

We searched the Cochrane Library, CENTRAL, MEDLINE, Embase, LILACS, World Health Organization International Clinical Trials Registry Platform and Opengrey up to April 2019. We also searched proceedings of eight congresses to a maximum of 10 years, and we contacted trial authors for additional information.

SELECTION CRITERIA

We included randomised clinical trials that included men and women, regardless of age, with definitive diagnoses of neurosyphilis, including HIV-seropositive patients. We compared any antibiotic regime (concentration, dose, frequency, duration), compared to any other antibiotic regime for the treatment for neurosyphilis in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible trials, extracted data, and evaluated risk of bias. We resolved disagreements by involving a third review author. For dichotomous data (serological cure, clinical cure, adverse events), we presented results as summary risk ratios (RR) with 95% confidence intervals (CI). We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

We identified one trial, with 36 participants​ diagnosed ​with syphilis and HIV. The participants were mainly men, with a median age of 34 years. This trial, ​funded by a pharmaceutical company, compared ceftriaxone in 18 participants (2 g daily for 10 days), with penicillin G, also in 18 participants (4 million/Units (MU)/intravenous (IV) every 4 hours for 10 days). The trial reported incomplete and inconclusive results. Three of 18 (16%) participants receiving ceftriaxone versus 2 of 18 (11%) receiving penicillin G achieved serological cure (RR 1.50; 95% CI: 0.28 to 7.93; 1 trial, 36 participants very low-quality evidence); and 8 of 18 (44%) participants receiving ceftriaxone versus 2 of 18 (18%) participants receiving penicillin G achieved clinical cure (RR 4.00; 95% CI: 0.98 to 16.30; 1 trial, 36 participants very low-quality evidence). Although more participants who received ceftriaxone achieved serological and clinical cure compared to those who received penicillin G, the evidence from this trial was insufficient to determine whether there was a difference between treatment with ceftriaxone or penicillin G.In this trial, the authors reported what would usually be adverse events as symptoms and signs in the follow-up of participants. Furthermore, this trial did not evaluate recurrence of neurosyphilis, time to recovery nor quality of life. We judged risk of bias in this clinical trial to be unclear for random sequence generation, allocation, ​and blinding of participants, and high for incomplete outcome data, potential conflicts of interest (funding bias), and other bias, due to the lack of a sample size calculation. We rated the quality of evidence as very low.

AUTHORS' CONCLUSIONS

Due to low quality and insufficient evidence, it was not possible to determine whether there was a difference between treatment with ceftriaxone or Penicillin G. Also, the benefits to people without HIV and neurosyphilis are unknown, as is the ceftriaxone safety profile.Therefore, these results should be interpreted with caution. This conclusion does not mean that antibiotics should not be used for treating this clinical entity. This Cochrane Review has identified the need of adequately powered trials, which should be planned according to Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) recommendations, conducted and reported as recommended by the CONSORT statement. Furthermore, the outcomes should be based on patients' perspectives taking into account Patient-Centered Outcomes Research Institute (PCORI) recommendations.

Aerobic and strength training exercise programme for cognitive impairment in people with mild to moderate dementia: the DAPA RCT

BACKGROUND

Approximately 670,000 people in the UK have dementia. Previous literature suggests that physical exercise could slow dementia symptom progression.

OBJECTIVES

To estimate the clinical effectiveness and cost-effectiveness of a bespoke exercise programme, in addition to usual care, on the cognitive impairment (primary outcome), function and health-related quality of life (HRQoL) of people with mild to moderate dementia (MMD) and carer burden and HRQoL.

DESIGN

Intervention development, systematic review, multicentred, randomised controlled trial (RCT) with a parallel economic evaluation and qualitative study.

SETTING

15 English regions.

PARTICIPANTS

People with MMD living in the community.

INTERVENTION

A 4-month moderate- to high-intensity, structured exercise programme designed specifically for people with MMD, with support to continue unsupervised physical activity thereafter. Exercises were individually prescribed and progressed, and participants were supervised in groups. The comparator was usual practice.

MAIN OUTCOME MEASURES

The primary outcome was the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog). The secondary outcomes were function [as measured using the Bristol Activities of Daily Living Scale (BADLS)], generic HRQoL [as measured using the EuroQol-5 Dimensions, three-level version (EQ-5D-3L)], dementia-related QoL [as measured using the Quality of Life in Alzheimer's Disease (QoL-AD) scale], behavioural symptoms [as measured using the Neuropsychiatric Inventory (NPI)], falls and fractures, physical fitness (as measured using the 6-minute walk test) and muscle strength. Carer outcomes were HRQoL (Quality of Life in Alzheimer's Disease) (as measured using the EQ-5D-3L) and carer burden (as measured using the Zarit Burden Interview). The economic evaluation was expressed in terms of incremental cost per quality-adjusted life-year (QALY) gained from a NHS and Personal Social Services perspective. We measured health and social care use with the Client Services Receipt Inventory. Participants were followed up for 12 months.

RESULTS

Between February 2013 and June 2015, 494 participants were randomised with an intentional unequal allocation ratio: 165 to usual care and 329 to the intervention. The mean age of participants was 77 years [standard deviation (SD) 7.9 years], 39% (193/494) were female and the mean baseline ADAS-Cog score was 21.5 (SD 9.0). Participants in the intervention arm achieved high compliance rates, with 65% (214/329) attending between 75% and 100% of sessions. Outcome data were obtained for 85% (418/494) of participants at 12 months, at which point a small, statistically significant negative treatment effect was found in the primary outcome, ADAS-Cog (patient reported), with a mean difference of -1.4 [95% confidence interval (CI) -2.62 to -0.17]. There were no treatment effects for any of the other secondary outcome measures for participants or carers: for the BADLS there was a mean difference of -0.6 (95% CI -2.05 to 0.78), for the EQ-5D-3L a mean difference of -0.002 (95% CI -0.04 to 0.04), for the QoL-AD scale a mean difference of 0.7 (95% CI -0.21 to 1.65) and for the NPI a mean difference of -2.1 (95% CI -4.83 to 0.65). Four serious adverse events were reported. The exercise intervention was dominated in health economic terms.

LIMITATIONS

In the absence of definitive guidance and rationale, we used a mixed exercise programme. Neither intervention providers nor participants could be masked to treatment allocation.

CONCLUSIONS

This is a large well-conducted RCT, with good compliance to exercise and research procedures. A structured exercise programme did not produce any clinically meaningful benefit in function or HRQoL in people with dementia or on carer burden.

FUTURE WORK

Future work should concentrate on approaches other than exercise to influence cognitive impairment in dementia.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN32612072.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full programme and will be published in full in Health Technology Assessment Vol. 22, No. 28. See the NIHR Journals Library website for further project information. Additional funding was provided by the Oxford NIHR Biomedical Research Centre and the Oxford NIHR Collaboration for Leadership in Applied Health Research and Care.

Estimating relative efficacy in acute postoperative pain: network meta-analysis is consistent with indirect comparison to placebo alone

Network meta-analysis uses direct comparisons of interventions within randomized controlled trials and indirect comparisons across them. Network meta-analysis uses more data than a series of direct comparisons with placebo, and theoretically should produce more reliable results. We used a Cochrane overview review of acute postoperative pain trials and other systematic reviews to provide data to test this hypothesis. Some 261 trials published between 1966 and 2016 included 39,753 patients examining 52 active drug and dose combinations (27,726 given active drug and 12,027 placebo), in any type of surgery (72% dental). Most trials were small; 42% of patients were in trials with arms <50 patients, and 27% in trials with arms ≥100 patients. Response to placebo in third molar extraction fell by half in studies over 30 to 40 years (171 trials, 7882 patients given placebo). Network meta-analysis and Cochrane analyses provided very similar results (average difference 0.04 number needed to treat units), with no significant difference for almost all comparisons apart from some with small patient numbers or small effect size, or both. Network meta-analysis did not detect significant differences between effective analgesics. The similarity between network meta-analysis and Cochrane indirect analyses probably arose from stringent quality criteria in trials accepted in Cochrane reviews (with consequent low risk of bias) and consistency in methods and outcomes. Network meta-analysis is a useful analytical tool that increases our confidence in estimates of efficacy of analgesics in acute postoperative pain, in this case by providing similar results.

Pregabalin for neuropathic pain in adults

BACKGROUND

This review updates part of an earlier Cochrane Review titled "Pregabalin for acute and chronic pain in adults", and considers only neuropathic pain (pain from damage to nervous tissue). Antiepileptic drugs have long been used in pain management. Pregabalin is an antiepileptic drug used in management of chronic pain conditions.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of pregabalin for chronic neuropathic pain in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, and Embase for randomised controlled trials from January 2009 to April 2018, online clinical trials registries, and reference lists.

SELECTION CRITERIA

We included randomised, double-blind trials of two weeks' duration or longer, comparing pregabalin (any route of administration) with placebo or another active treatment for neuropathic pain, with participant-reported pain assessment.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality and biases. Primary outcomes were: at least 30% pain intensity reduction over baseline; much or very much improved on the Patient Global Impression of Change (PGIC) Scale (moderate benefit); at least 50% pain intensity reduction; or very much improved on PGIC (substantial benefit). We calculated risk ratio (RR) and number needed to treat for an additional beneficial (NNTB) or harmful outcome (NNTH). We assessed the quality of the evidence using GRADE.

MAIN RESULTS

We included 45 studies lasting 2 to 16 weeks, with 11,906 participants - 68% from 31 new studies. Oral pregabalin doses of 150 mg, 300 mg, and 600 mg daily were compared with placebo. Postherpetic neuralgia, painful diabetic neuropathy, and mixed neuropathic pain predominated (85% of participants). High risk of bias was due mainly to small study size (nine studies), but many studies had unclear risk of bias, mainly due to incomplete outcome data, size, and allocation concealment.Postherpetic neuralgia: More participants had at least 30% pain intensity reduction with pregabalin 300 mg than with placebo (50% vs 25%; RR 2.1 (95% confidence interval (CI) 1.6 to 2.6); NNTB 3.9 (3.0 to 5.6); 3 studies, 589 participants, moderate-quality evidence), and more had at least 50% pain intensity reduction (32% vs 13%; RR 2.5 (95% CI 1.9 to 3.4); NNTB 5.3 (3.9 to 8.1); 4 studies, 713 participants, moderate-quality evidence). More participants had at least 30% pain intensity reduction with pregabalin 600 mg than with placebo (62% vs 24%; RR 2.5 (95% CI 2.0 to 3.2); NNTB 2.7 (2.2 to 3.7); 3 studies, 537 participants, moderate-quality evidence), and more had at least 50% pain intensity reduction (41% vs 15%; RR 2.7 (95% CI 2.0 to 3.5); NNTB 3.9 (3.1 to 5.5); 4 studies, 732 participants, moderate-quality evidence). Somnolence and dizziness were more common with pregabalin than with placebo (moderate-quality evidence): somnolence 300 mg 16% versus 5.5%, 600 mg 25% versus 5.8%; dizziness 300 mg 29% versus 8.1%, 600 mg 35% versus 8.8%.Painful diabetic neuropathy: More participants had at least 30% pain intensity reduction with pregabalin 300 mg than with placebo (47% vs 42%; RR 1.1 (95% CI 1.01 to 1.2); NNTB 22 (12 to 200); 8 studies, 2320 participants, moderate-quality evidence), more had at least 50% pain intensity reduction (31% vs 24%; RR 1.3 (95% CI 1.2 to 1.5); NNTB 22 (12 to 200); 11 studies, 2931 participants, moderate-quality evidence), and more had PGIC much or very much improved (51% vs 30%; RR 1.8 (95% CI 1.5 to 2.0); NNTB 4.9 (3.8 to 6.9); 5 studies, 1050 participants, moderate-quality evidence). More participants had at least 30% pain intensity reduction with pregabalin 600 mg than with placebo (63% vs 52%; RR 1.2 (95% CI 1.04 to 1.4); NNTB 9.6 (5.5 to 41); 2 studies, 611 participants, low-quality evidence), and more had at least 50% pain intensity reduction (41% vs 28%; RR 1.4 (95% CI 1.2 to 1.7); NNTB 7.8 (5.4 to 14); 5 studies, 1015 participants, low-quality evidence). Somnolence and dizziness were more common with pregabalin than with placebo (moderate-quality evidence): somnolence 300 mg 11% versus 3.1%, 600 mg 15% versus 4.5%; dizziness 300 mg 13% versus 3.8%, 600 mg 22% versus 4.4%.Mixed or unclassified post-traumatic neuropathic pain: More participants had at least 30% pain intensity reduction with pregabalin 600 mg than with placebo (48% vs 36%; RR 1.2 (1.1 to 1.4); NNTB 8.2 (5.7 to 15); 4 studies, 1367 participants, low-quality evidence), and more had at least 50% pain intensity reduction (34% vs 20%; RR 1.5 (1.2 to 1.9); NNTB 7.2 (5.4 to 11); 4 studies, 1367 participants, moderate-quality evidence). Somnolence (12% vs 3.9%) and dizziness (23% vs 6.2%) were more common with pregabalin.Central neuropathic pain: More participants had at least 30% pain intensity reduction with pregabalin 600 mg than with placebo (44% vs 28%; RR 1.6 (1.3 to 2.0); NNTB 5.9 (4.1 to 11); 3 studies, 562 participants, low-quality evidence) and at least 50% pain intensity reduction (26% vs 15%; RR 1.7 (1.2 to 2.3); NNTB 9.8 (6.0 to 28); 3 studies, 562 participants, low-quality evidence). Somnolence (32% vs 11%) and dizziness (23% vs 8.6%) were more common with pregabalin.Other neuropathic pain conditions: Studies show no evidence of benefit for 600 mg pregabalin in HIV neuropathy (2 studies, 674 participants, moderate-quality evidence) and limited evidence of benefit in neuropathic back pain or sciatica, neuropathic cancer pain, or polyneuropathy.Serious adverse events, all conditions: Serious adverse events were no more common with placebo than with pregabalin 300 mg (3.1% vs 2.6%; RR 1.2 (95% CI 0.8 to 1.7); 17 studies, 4112 participants, high-quality evidence) or pregabalin 600 mg (3.4% vs 3.4%; RR 1.1 (95% CI 0.8 to 1.5); 16 studies, 3995 participants, high-quality evidence).

AUTHORS' CONCLUSIONS

Evidence shows efficacy of pregabalin in postherpetic neuralgia, painful diabetic neuralgia, and mixed or unclassified post-traumatic neuropathic pain, and absence of efficacy in HIV neuropathy; evidence of efficacy in central neuropathic pain is inadequate. Some people will derive substantial benefit with pregabalin; more will have moderate benefit, but many will have no benefit or will discontinue treatment. There were no substantial changes since the 2009 review.

Acetyl-L-carnitine for patients with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a common and devastating neuropsychiatric complication of acute liver failure or chronic liver disease. Ammonia content in the blood seems to play a role in the development of hepatic encephalopathy. Treatment for hepatic encephalopathy is complex. Acetyl-L-carnitine is a substance that may reduce ammonia toxicity. This review assessed the benefits and harms of acetyl-L-carnitine for patients with hepatic encephalopathy.

OBJECTIVES

To assess the benefits and harms of acetyl-L-carnitine for patients with hepatic encephalopathy.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, and Science Citation Index Expanded for randomised clinical trials. We sought additional randomised clinical trials from the World Health Organization Clinical Trials Search Portal and ClinicalTrials.gov. We performed all electronic searches until 10 September 2018. We looked through the reference lists of retrieved publications and review articles, and we searched the FDA and EMA websites.

SELECTION CRITERIA

We searched for randomised clinical trials in any setting, recruiting people with hepatic encephalopathy. Trials were eligible for inclusion if they compared acetyl-L-carnitine plus standard care (e.g. antibiotics, lactulose) versus placebo or no acetyl-L-carnitine plus standard care. We are well aware that by selecting randomised clinical trials, we placed greater focus on potential benefits than on potential harms.

DATA COLLECTION AND ANALYSIS

We selected randomised clinical trials, assessed risk of bias in eight domains, and extracted data in a duplicate and independent fashion. We estimated risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes. We measured statistical heterogeneity using I² and D² statistics. We subjected our analyses to fixed-effect and random-effects model meta-analyses. We assessed bias risk domains to control systematic errors. We assessed overall quality of the data for each individual outcome by using the GRADE approach.

MAIN RESULTS

We identified five randomised clinical trials involving 398 participants. All trials included only participants with cirrhosis as the underlying cause of hepatic encephalopathy. Trials included participants with covert or overt hepatic encephalopathy. All trials were conducted in Italy by a single team and assessed acetyl-L-carnitine compared with placebo. Oral intervention was the most frequent route of administration. All trials were at high risk of bias and were underpowered. None of the trials were sponsored by the pharmaceutical industry.None of the identified trials reported information on all-cause mortality, serious adverse events, or days of hospitalisation. Only one trial assessed quality of life using the Short Form (SF)-36 scale (67 participants; very low-quality evidence). The effects of acetyl-L-carnitine compared with placebo on general health at 90 days are uncertain (MD -6.20 points, 95% confidence interval (CI) -9.51 to -2.89). Results for additional domains of the SF-36 are also uncertain. One trial assessed fatigue using the Wessely and Powell test (121 participants; very low-quality evidence). The effects are uncertain in people with moderate-grade hepatic encephalopathy (mental fatigue: MD 0.40 points, 95% CI -0.21 to 1.01; physical fatigue: MD -0.20 points, 95% CI -0.92 to 0.52) and mild-grade hepatic encephalopathy (mental fatigue: -0.80 points, 95% CI -1.48 to -0.12; physical fatigue: 0.20 points, 95% CI -0.72 to 1.12). Meta-analysis showed a reduction in blood ammonium levels favouring acetyl-L-carnitine versus placebo (MD -13.06 mg/dL, 95% CI -17.24 to -8.99; 387 participants; 5 trials; very low-quality evidence). It is unclear whether acetyl-L-carnitine versus placebo increases the risk of non-serious adverse events (8/126 (6.34%) vs 3/120 (2.50%); RR 2.51, 95% CI 0.68 to 9.22; 2 trials; very low-quality evidence). Overall, adverse events data were poorly reported and harms may have been underestimated.

AUTHORS' CONCLUSIONS

This Cochrane systematic review analysed a heterogeneous group of five trials at high risk of bias and with high risk of random errors conducted by only one research team. We assessed acetyl-L-carnitine versus placebo in participants with cirrhosis with covert or overt hepatic encephalopathy. Hence, we have no data on the drug for hepatic encephalopathy in acute liver failure. We found no information about all-cause mortality, serious adverse events, or days of hospitalisation. We found no clear differences in effect between acetyl-L-carnitine and placebo regarding quality of life, fatigue, and non-serious adverse events. Acetyl-L-carnitine reduces blood ammonium levels compared with placebo. We rated all evidence as of very low quality due to pitfalls in design and execution, inconsistency, small sample sizes, and very few events. The harms profile for acetyl-L-carnitine is presently unclear. Accordingly, we need further randomised clinical trials to assess acetyl-L-carnitine versus placebo conducted according to the SPIRIT statements and reported according to the CONSORT statements.

Acceptance and treatment effects of an internet-delivered cognitive-behavioral intervention for family caregivers of people with dementia: A randomized-controlled trial

OBJECTIVES

The study evaluated the efficacy of an internet-delivered cognitive-behavioral intervention for caregivers of people with dementia and examined acceptance of program characteristics.

METHOD

Thirty-nine caregivers (M _age  = 62.11 ± 9.67, 78.4% female) were enrolled in a 2 × 3 randomized-controlled trial (RCT) that compared an intervention and wait-list control group. A cognitive-behavioral intervention program was adapted for delivery via an internet platform. Participants exchanged eight weekly messages with a therapist.

RESULTS

Treatment satisfaction and acceptance of the program were high. Well-being increased over the intervention duration and intervention group participants were better able to cope with the anticipated death of the care recipient and utilized more psychosocial resources after the intervention ended. Effects were not maintained until follow-up and there were no treatment effects for depression and burden of care.

CONCLUSIONS

Internet-delivered cognitive-behavioral interventions are suitable for caregivers. A larger RCT needs to investigate possible combinations of classic and internet-delivered programs and confirm efficacy.

Micro-Particle Curcumin for the Treatment of Chronic Kidney Disease-1: Study Protocol for a Multicenter Clinical Trial

Background

The progression to end-stage renal disease (ESRD) is the most important complication of chronic kidney disease (CKD). Patients with ESRD require dialysis or transplantation to survive, incur numerous complications, and have high mortality rates. Slowing the progression of CKD is an important goal. Unfortunately, even when current treatments are appropriately applied, patients with CKD still progress to ESRD. Current treatments do not address the inflammation and fibrosis that mediate progression to ESRD, but micro-particle curcumin, a natural health product, has both anti-inflammatory and anti-fibrotic properties and may be an effective treatment for patients with CKD.

Objective

Micro-particle curcumin for the treatment of CKD-1 (MPAC-CKD-1) will measure the effect of micro-particle curcumin on 2 important markers of CKD progression: albuminuria and estimated glomerular filtration rate (eGFR). Efficacy in either of these markers will justify a larger, international trial to investigate micro-particle curcumin's ability to lower the risk of ESRD in patients with CKD.

Design

MPAC-CKD-1 is a multicenter, double-blind prospective randomized controlled trial.

Setting

Four kidney disease clinics in Ontario, Canada (3 in London and 1 in Hamilton).

Patients

We will enroll patients with CKD, defined by an eGFR between 15 and 60 mL/min/1.73 m² and a daily albumin excretion of more than 300 mg (or a random urine sample albumin-to-creatinine ratio more than 30 mg/mmol).

Measurements

We will measure changes in the co-primary outcomes of urinary albumin-to-creatinine ratio and eGFR at 3 months and 6 months. We will also measure compliance, safety parameters, and changes in health-related quality of life.

Methods

Participants will be randomly assigned to receive micro-particle curcumin 90 mg once daily or matching placebo for 6 months. We will enroll at least 500 patients to exclude clinically meaningful 6-month changes in these 2 co-primary outcomes (16% difference in albuminuria, and a 2.3 mL/min/1.73 m² between-group difference in the 6-month change in eGFR, at a two-tailed alpha of 0.025, power of 0.80).

Results

Patient enrollment began on October 1, 2015, with 414 participants randomized as of July 2018. We expect to report the results in 2020.

Limitations

MPAC-CKD-1 is not powered to assess outcomes such as the need for renal replacement therapy or death.

Conclusions

MPAC-CKD-1 is a multicenter, double-blind prospective randomized controlled trial designed to test whether micro-particle curcumin reduces albuminuria and slows eGFR decline in patients with albuminuric CKD. MPAC-CKD-1 will also test the feasibility of this intervention and inform the need for a future larger scale trial (MPAC-CKD-2).

Trial registration

MPAC-CKD-1 is registered with U.S. National Institutes of Health at clinicaltrials.gov (NCT02369549). Protocol version 2.0, December 6, 2014.

Early mobilisation by head-up tilt with stepping versus standard care after severe traumatic brain injury - Protocol for a randomised clinical feasibility trial

Background

Intensive rehabilitation of patients with severe traumatic brain injury is generally applied in the subacute stages of the hospital stay. Few studies have assessed the association between early and intensive physical rehabilitation and functional outcomes. The aim of this trial is to assess the feasibility of an intensive physical rehabilitation intervention focusing on mobilisation to the upright position, starting as early as clinically possible versus standard care in the intensive care unit. The feasibility study is intended to inform a subsequent randomised clinical trial that will investigate benefits and harms of the intervention.

Methods

This randomised clinical feasibility trial with a follow-up period of 1 year will use blinded outcome assessors for the Coma Recovery Scale–Revised. A maximum of 60 patients admitted to the neurointensive care unit at Rigshospitalet, Denmark, with traumatic brain injury (age of at least 18 years), a low level of consciousness, and stable intracranial pressure will be included in the trial. Patients will be randomly assigned to experimental intervention versus standard care (1:1) stratified according to their Glasgow Coma Score. The intervention group will receive daily mobilisation in a tilt table with an integrated stepping device (ERIGO^®). Feasibility is declared if more than 60% (the lower 95% confidence interval of the proportion) of eligible patients are included in the trial and more than 52% (the lower 95% confidence interval of the proportion) of patients in the intervention group receive more than 60% of the planned interventions. Safety is assessed by the occurrence of adverse events and adverse reactions. Exploratory clinical outcomes consist of cerebral haemodynamics (blood flow velocity and pressure autoregulation) and baroreceptor sensitivity in the early phase as well as functional outcomes (Coma Recovery Scale–Revised, Early Functional Ability scale, and Functional Independence Measure).

Discussion

Our findings will inform a future, larger-scale randomised clinical trial on early mobilisation using a tilt table early after severe traumatic brain injury.

Trial registration

ClinicalTrials.gov identifier: NCT02924649. Registered on 3 October 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3004-x) contains supplementary material, which is available to authorized users.

Prothrombin complex concentrate versus placebo, no intervention, or other interventions in critically bleeding patients associated with oral anticoagulant administration: a protocol for a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis

BACKGROUND

Acute critical bleeding is one of the most feared complications during treatment with oral anticoagulating agents. As more patients undergo treatment with anticoagulating agents, critically bleeding episodes in patients with vitamin K antagonists, thrombin inhibitor, or factor Xa inhibitor-inducted coagulopathy will be encountered frequently by physicians. Hence, an effective treatment capable of reversing the iatrogenic coagulopathy in the acute setting is needed. In randomised clinical trials and observational studies, prothrombin complex concentrate has been reported to be superior to other acute interventions, and many guidelines recommend prothrombin complex concentrate in treatment of critically bleeding patients. The aim of this systematic review is to synthesise the evidence of the effects of prothrombin complex concentrate compared with placebo, no intervention, or other treatment options in critically bleeding patients treated with oral anticoagulants.

METHODS/DESIGN

A comprehensive search for relevant published literature will be undertaken in Cochrane Central Register of Controlled Trials, MEDLINE, Embase, WHO International Clinical Trials Registry Platform, Science Citation Index, regulatory databases, and trial registers. We will include randomised clinical trials comparing prothrombin complex concentrate versus placebo, no intervention, or other interventions in critically bleeding patients with oral anticoagulant-induced coagulopathy. Data extraction and risk of bias assessment will be handled by two independent review authors. Meta-analysis will be performed as recommended by Cochrane Handbook for Systematic Reviews of Interventions, bias will be assessed with domains, and trial sequential analysis will be conducted to control random errors. Certainty will be assessed by GRADE.

DISCUSSION

As critical bleeding in patients treated with oral anticoagulants is an increasing problem, an up-to-date systematic review evaluating the benefits and harms of prothrombin complex concentrate is urgently needed. It is the hope that this review will be able to guide best practice in treatment and clinical research of these critically bleeding patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018084371.

Randomized controlled trials: significant results-fragile, though

In their systematic review, Shochet et al. question the robustness of the statistical significance of the results of randomized controlled trials (RCTs) in nephrology reported in high-impact journals (2005-2014). They hypothesized that a high proportion of RCTs in nephrology would be fragile. They calculated a Fragility Index that is a tool for testing robustness of RCTs, based on 107 RCT reports. The observation of an alarming median Fragility Index equal to 3 suggests that in half of the trials, the sole additional occurrence of 3 events would compromise the significance of nominally significant results.

Botulinum toxins for the prevention of migraine in adults

BACKGROUND

Migraine occurs in around 15% of adults and is ranked as the seventh most disabling disease amongst all diseases globally. Despite the available treatments many people suffer prolonged and frequent attacks which have a major impact on their quality of life. Chronic migraine is defined as 15 or more days of headache per month, at least eight of those days being migraine. People with episodic migraine have fewer than 15 headache days per month. Botulinum toxin type A has been licensed in some countries for chronic migraine treatment, due to the results of just two trials.

OBJECTIVES

To assess the effects of botulinum toxins versus placebo or active treatment for the prevention or reduction in frequency of chronic or episodic migraine in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE & MEDLINE in Process, Embase, ClinicalTrials.gov and World Health Organization International Clinical Trials Registry (to December 2017). We examined reference lists and carried out citation searches on key publications. We sent correspondence to major manufacturers of botulinum toxin.

SELECTION CRITERIA

Randomised, double-blind, controlled trials of botulinum toxin (any sero-type) injections into the head and neck for prophylaxis of chronic or episodic migraine in adults. Eligible comparators were placebo, alternative prophylactic agent or different dose of botulinum toxin.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data. For continuous outcomes we used mean change data when available. For dichotomous data we calculated risk ratios (RRs). We used data from the 12-week post-treatment follow-up time point. We assessed the evidence using GRADE and created two 'Summary of findings' tables.

MAIN RESULTS

Description of trialsWe found 90 articles describing 28 trials (4190 participants), which were eligible for inclusion. The longest treatment duration was three rounds of injections with three months between treatments, so we could not analyse long-term effects. For the primary analyses, we pooled data from both chronic and episodic participant populations. Where possible, we also separated data into chronic migraine, episodic migraine and 'mixed group' classification subgroups. Most trials (21 out of 28) were small (fewer than 50 participants per trial arm). The risk of bias for included trials was low or unclear across most domains, with some trials reporting a high risk of bias for incomplete outcome data and selective outcome reporting.Botulinum toxin versus placeboTwenty-three trials compared botulinum toxin with placebo. Botulinum toxin may reduce the number of migraine days per month in the chronic migraine population by 3.1 days (95% confidence interval (CI) -4.7 to -1.4, 4 trials, 1497 participants, low-quality evidence). This was reduced to -2 days (95% CI -2.8 to -1.1, 2 trials, 1384 participants; moderate-quality evidence) when we removed small trials.A single trial of people with episodic migraine (N = 418) showed no difference between groups for this outcome measure (P = 0.49).In the chronic migraine population, botulinum toxin reduces the number of headache days per month by 1.9 days (95% CI -2.7 to -1.0, 2 trials, 1384 participants, high-quality evidence). We did not find evidence of a difference in the number of migraine attacks for both chronic and episodic migraine participants (6 trials, N = 2004, P = 0.30, low-quality evidence). For the population of both chronic and episodic migraine participants a reduction in severity of migraine rated during clinical visits, on a 10 cm visual analogue scale (VAS) of 3.3 cm (95% CI -4.2 to -2.5, very low-quality evidence) in favour of botulinum toxin treatment came from four small trials (N = 209); better reporting of this outcome measure from the additional eight trials that recorded it may have improved our confidence in the pooled estimate. Global assessment and quality-of-life measures were poorly reported and it was not possible to carry out statistical analysis of these outcome measures. Analysis of adverse events showed an increase in the risk ratio with treatment with botulinum toxin over placebo 30% (RR 1.28, 95% CI 1.12 to 1.47, moderate-quality evidence). For every 100 participants 60 experienced an adverse event in the botulinum toxin group compared with 47 in the placebo group.Botulinum toxin versus other prophylactic agentThree trials studied comparisons with alternative oral prophylactic medications. Meta-analyses were not possible for number of migraine days, number of headache days or number of migraine attacks due to insufficient data, but individually trials reported no differences between groups for a variety of efficacy measures in the population of both chronic and episodic migraine participants. The global impression of disease measured using Migraine Disability Assessment (MIDAS) scores were reported from two trials that showed no difference between groups. Compared with oral treatments, botulinum toxin showed no between-group difference in the risk of adverse events (2 trials, N = 114, very low-quality evidence). The relative risk reduction (RRR) for withdrawing from botulinum toxin due to adverse events compared with the alternative prophylactic agent was 72% (P = 0.02, 2 trials, N = 119).Dosing trialsThere were insufficient data available for the comparison of different doses.Quality of the evidenceThe quality of the evidence assessed using GRADE methods was varied but mostly very low; the quality of the evidence for the placebo and active control comparisons was low and very low, respectively for the primary outcome measure. Small trial size, high risk of bias and unexplained heterogeneity were common reasons for downgrading the quality of the evidence.

AUTHORS' CONCLUSIONS

In chronic migraine, botulinum toxin type A may reduce the number of migraine days per month by 2 days compared with placebo treatment. Non-serious adverse events were probably experienced by 60/100 participants in the treated group compared with 47/100 in the placebo group. For people with episodic migraine, we remain uncertain whether or not this treatment is effective because the quality of this limited evidence is very low. Better reporting of outcome measures in published trials would provide a more complete evidence base on which to draw conclusions.

Antibiotics for treating gonorrhoea in pregnancy

BACKGROUND

Gonorrhoea is a sexually transmitted infection that is caused by Neisseria gonorrhoeae, and is a major public health challenge today. N gonorrhoeae can be transmitted from the mother's genital tract to the newborn during birth, and can cause gonococcal ophthalmia neonatorum as well as systemic neonatal infections. It can also cause endometritis and pelvic sepsis in the mother. This review updates and replaces an earlier Cochrane Review on antibiotics for treating this infectious condition.

OBJECTIVES

To assess the clinical effectiveness and harms of antibiotics for treating gonorrhoea in pregnant women.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2017), LILACS database (1982 to April 5, 2017), the WHO International Clinical Trials Registry Platform (ICTRP; April 5, 2017), ClinicalTrials.gov (April 5, 2017), the ISRCTN Registry (April 5, 2017), and Epistemonikos (April 5, 2017). We also searched reference lists of all retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing the use of antibiotics for treating gonorrhoea in pregnancy. The antibiotics could have been used alone or in combination, were administered parenterally, orally, or both, and were compared with another antibiotic.We included RCTs regardless of their publication status (published, unpublished, published as an article, an abstract, or a letter), language, or country. We applied no limits on the length of follow-up.We excluded RCTs using a cluster- or cross-over design, or quasi-RCTs.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy.

MAIN RESULTS

We included two RCTs, that randomised 514 pregnant women (347 women analysed) at a mean gestational age of 22 weeks. Both trials were conducted in the outpatient department of the same two hospitals in the USA between 1993 and 2001, and had a follow-up of 14 days. One of the trials was sponsored by a drug company. We considered both trials to be at a high risk of bias.One trial compared ceftriaxone (125 mg, intramuscular) with cefixime (400 mg, oral); the other trial had three arms, and assessed ceftriaxone (250 mg, intramuscular) versus either amoxicillin (3 g, oral) plus probenecid (1 g, oral) or spectinomycin (2 g, intramuscular). We did not include the spectinomycin data because this medication is no longer produced. We were unable to conduct meta-analysis because the trials compared different medications.We found inconclusive evidence that there were clear differences in the cure of gonococcal infections (genital, extragenital, or both) between intramuscular ceftriaxone versus oral amoxicillin plus oral probenecid (risk ratio (RR) 1.07, 95% confidence interval (CI) 0.98 to 1.16; one RCT; 168 women; very low-quality evidence) or intramuscular ceftriaxone versus oral cefixime (RR 0.99, 95% CI 0.91 to 1.08; one RCT; 95 women; very low-quality evidence).Neither of the trials reported on two of this review's primary maternal outcomes: incidence of obstetric complications (miscarriage, premature rupture of membranes, preterm delivery, or fetal death), or disseminated gonococcal infection, or on the incidence of neonatorum ophthalmia in the neonates.One trial reported one case of vomiting in the oral amoxacillin plus probenecid group. Trials reported pain at the injection sites, but did not quantify it. Hyperberbilurrubinemia was more frequent in neonates whose mothers were exposed to ceftriaxone. There were no clear differences between groups for neonatal malformation.

AUTHORS' CONCLUSIONS

This Cochrane Review found high levels of cure of gonococcal infections in pregnancy with the given antibiotic regimens. However, the evidence in this review is inconclusive as it does not support one particular regimen over another. This conclusion was based on very low-quality evidence (downgraded for poor trial design, imprecision) from two trials (involving 514 women), which we assessed to be at a high risk of bias for a number of domains. The harm profiles of the antibiotic regimes featured in this review remain unknown.High-quality RCTs are needed, with sufficient power to assess the clinical effectiveness and potential harms of antibiotics in pregnant women with gonorrhoea. These should be planned according to Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT),conducted following CONSORT recommendations, and based on Patient-Centered Outcomes Research Institute (PCORI) outcomes.

Randomized clinical trials in dentistry: Risks of bias, risks of random errors, reporting quality, and methodologic quality over the years 1955-2013

OBJECTIVES

To examine the risks of bias, risks of random errors, reporting quality, and methodological quality of randomized clinical trials of oral health interventions and the development of these aspects over time.

METHODS

We included 540 randomized clinical trials from 64 selected systematic reviews. We extracted, in duplicate, details from each of the selected randomized clinical trials with respect to publication and trial characteristics, reporting and methodologic characteristics, and Cochrane risk of bias domains. We analyzed data using logistic regression and Chi-square statistics.

RESULTS

Sequence generation was assessed to be inadequate (at unclear or high risk of bias) in 68% (n = 367) of the trials, while allocation concealment was inadequate in the majority of trials (n = 464; 85.9%). Blinding of participants and blinding of the outcome assessment were judged to be inadequate in 28.5% (n = 154) and 40.5% (n = 219) of the trials, respectively. A sample size calculation before the initiation of the study was not performed/reported in 79.1% (n = 427) of the trials, while the sample size was assessed as adequate in only 17.6% (n = 95) of the trials. Two thirds of the trials were not described as double blinded (n = 358; 66.3%), while the method of blinding was appropriate in 53% (n = 286) of the trials. We identified a significant decrease over time (1955-2013) in the proportion of trials assessed as having inadequately addressed methodological quality items (P < 0.05) in 30 out of the 40 quality criteria, or as being inadequate (at high or unclear risk of bias) in five domains of the Cochrane risk of bias tool: sequence generation, allocation concealment, incomplete outcome data, other sources of bias, and overall risk of bias.

CONCLUSIONS

The risks of bias, risks of random errors, reporting quality, and methodological quality of randomized clinical trials of oral health interventions have improved over time; however, further efforts that contribute to the development of more stringent methodology and detailed reporting of trials are still needed.

When and how should multiple imputation be used for handling missing data in randomised clinical trials - a practical guide with flowcharts

Background

Missing data may seriously compromise inferences from randomised clinical trials, especially if missing data are not handled appropriately. The potential bias due to missing data depends on the mechanism causing the data to be missing, and the analytical methods applied to amend the missingness. Therefore, the analysis of trial data with missing values requires careful planning and attention.

Methods

The authors had several meetings and discussions considering optimal ways of handling missing data to minimise the bias potential. We also searched PubMed (key words: missing data; randomi*; statistical analysis) and reference lists of known studies for papers (theoretical papers; empirical studies; simulation studies; etc.) on how to deal with missing data when analysing randomised clinical trials.

Results

Handling missing data is an important, yet difficult and complex task when analysing results of randomised clinical trials. We consider how to optimise the handling of missing data during the planning stage of a randomised clinical trial and recommend analytical approaches which may prevent bias caused by unavoidable missing data. We consider the strengths and limitations of using of best-worst and worst-best sensitivity analyses, multiple imputation, and full information maximum likelihood. We also present practical flowcharts on how to deal with missing data and an overview of the steps that always need to be considered during the analysis stage of a trial.

Conclusions

We present a practical guide and flowcharts describing when and how multiple imputation should be used to handle missing data in randomised clinical.

Electronic supplementary material

The online version of this article (10.1186/s12874-017-0442-1) contains supplementary material, which is available to authorized users.

Oral nonsteroidal anti-inflammatory drugs (NSAIDs) for cancer pain in adults

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Non-opioid drugs are commonly used to treat cancer pain, and are recommended for this purpose in the World Health Organization (WHO) cancer pain treatment ladder, either alone or in combination with opioids.A previous Cochrane review that examined the evidence for nonsteroidal anti-inflammatory drugs (NSAIDs) or paracetamol, alone or combined with opioids, for cancer pain was withdrawn in 2015 because it was out of date; the date of the last search was 2005. This review, and another on paracetamol, updates the evidence.

OBJECTIVES

To assess the efficacy of oral NSAIDs for cancer pain in adults, and the adverse events reported during their use in clinical trials.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to April 2017, together with reference lists of retrieved papers and reviews, and two online study registries.

SELECTION CRITERIA

We included randomised, double-blind, single-blind, or open-label studies of five days' duration or longer, comparing any oral NSAID alone with placebo or another NSAID, or a combination of NSAID plus opioid with the same dose of the opioid alone, for cancer pain of any pain intensity. The minimum study size was 25 participants per treatment arm at the initial randomisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Eleven studies satisfied inclusion criteria, lasting one week or longer; 949 participants with mostly moderate or severe pain were randomised initially, but fewer completed treatment or had results of treatment. Eight studies were double-blind, two single-blind, and one open-label. None had a placebo only control; eight compared different NSAIDs, three an NSAID with opioid or opioid combination, and one both. None compared an NSAID plus opioid with the same dose of opioid alone. Most studies were at high risk of bias for blinding, incomplete outcome data, or small size; none was unequivocally at low risk of bias.It was not possible to compare NSAIDs as a group with another treatment, or one NSAID with another NSAID. Results for all NSAIDs are reported as a randomised cohort. We judged results for all outcomes as very low-quality evidence.None of the studies reported our primary outcomes of participants with pain reduction of at least 50%, and at least 30%, from baseline; participants with Patient Global Impression of Change (PGIC) of much improved or very much improved (or equivalent wording). With NSAID, initially moderate or severe pain was reduced to no worse than mild pain after one or two weeks in four studies (415 participants in total), with a range of estimates between 26% and 51% in individual studies.Adverse event and withdrawal reporting was inconsistent. Two serious adverse events were reported with NSAIDs, and 22 deaths, but these were not clearly related to any pain treatment. Common adverse events were thirst/dry mouth (15%), loss of appetite (14%), somnolence (11%), and dyspepsia (11%). Withdrawals were common, mostly because of lack of efficacy (24%) or adverse events (5%).

AUTHORS' CONCLUSIONS

There is no high-quality evidence to support or refute the use of NSAIDs alone or in combination with opioids for the three steps of the three-step WHO cancer pain ladder. There is very low-quality evidence that some people with moderate or severe cancer pain can obtain substantial levels of benefit within one or two weeks.

Oral paracetamol (acetaminophen) for cancer pain

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Non-opioid drugs are commonly used to treat mild to moderate cancer pain, and are recommended for this purpose in the WHO cancer pain treatment ladder, either alone or in combination with opioids.A previous Cochrane review that examined the evidence for nonsteroidal anti-inflammatory drugs (NSAIDs) or paracetamol, alone or combined with opioids, for cancer pain was withdrawn in 2015 because it was out of date; the date of the last search was 2005. This review, and another on NSAIDs, updates the evidence.

OBJECTIVES

To assess the efficacy of oral paracetamol (acetaminophen) for cancer pain in adults and children, and the adverse events reported during its use in clinical trials.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to March 2017, together with reference lists of retrieved papers and reviews, and two online study registries.

SELECTION CRITERIA

We included randomised, double-blind, studies of five days' duration or longer, comparing paracetamol alone with placebo, or paracetamol in combination with an opioid compared with the same dose of the opioid alone, for cancer pain of any intensity. Single-blind and open studies were also eligible for inclusion. The minimum study size was 25 participants per treatment arm at the initial randomisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Three studies in adults satisfied the inclusion criteria, lasting up to one week; 122 participants were randomised initially, and 95 completed treatment. We found no studies in children. One study was parallel-group, and two had a cross-over design. All used paracetamol as an add-on to established treatment with strong opioids (median daily morphine equivalent doses of 60 mg, 70 mg, and 225 mg, with some participants taking several hundred mg of oral morphine equivalents daily). Other non-paracetamol medication included non-steroidal anti-inflammatory drugs (NSAIDs), tricyclic antidepressants, or neuroleptics. All studies were at high risk of bias for incomplete outcome data and small size; none was unequivocally at low risk of bias.None of the studies reported any of our primary outcomes: participants with pain reduction of at least 50%, and at least 30%, from baseline; participants with pain no worse than mild at the end of the treatment period; participants with Patient Global Impression of Change (PGIC) of much improved or very much improved (or equivalent wording). What pain reports there were indicated no difference between paracetamol and placebo when added to another treatment. There was no convincing evidence of paracetamol being different from placebo with regards to quality of life, use of rescue medication, or participant satisfaction or preference. Measures of harm (serious adverse events, other adverse events, and withdrawal due to lack of efficacy) were inconsistently reported and provided no clear evidence of difference.Our GRADE assessment of evidence quality was very low for all outcomes, because studies were at high risk of bias from several sources.

AUTHORS' CONCLUSIONS

There is no high-quality evidence to support or refute the use of paracetamol alone or in combination with opioids for the first two steps of the three-step WHO cancer pain ladder. It is not clear whether any additional analgesic benefit of paracetamol could be detected in the available studies, in view of the doses of opioids used.

Opioids for cancer pain - an overview of Cochrane reviews

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Opioid (morphine-like) drugs are commonly used to treat moderate or severe cancer pain, and are recommended for this purpose in the World Health Organization (WHO) pain treatment ladder. The most commonly-used opioid drugs are buprenorphine, codeine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, oxycodone, tramadol, and tapentadol.

OBJECTIVES

To provide an overview of the analgesic efficacy of opioids in cancer pain, and to report on adverse events associated with their use.

METHODS

We identified systematic reviews examining any opioid for cancer pain published to 4 May 2017 in the Cochrane Database of Systematic Reviews in the Cochrane Library. The primary outcomes were no or mild pain within 14 days of starting treatment, withdrawals due to adverse events, and serious adverse events.

MAIN RESULTS

We included nine reviews with 152 included studies and 13,524 participants, but because some studies appeared in more than one review the number of unique studies and participants was smaller than this. Most participants had moderate or severe pain associated with a range of different types of cancer. Studies in the reviews typically compared one type of opioid or formulation with either a different formulation of the same opioid, or a different opioid; few included a placebo control. Typically the reviews titrated dose to effect, a balance between pain relief and adverse events. Various routes of administration of opioids were considered in the reviews; oral with most opioids, but transdermal administration with fentanyl, and buprenorphine. No review included studies of subcutaneous opioid administration. Pain outcomes reported were varied and inconsistent. The average size of included studies varied considerably between reviews: studies of older opioids, such as codeine, morphine, and methadone, had low average study sizes while those involving newer drugs tended to have larger study sizes.Six reviews reported a GRADE assessment (buprenorphine, codeine, hydromorphone, methadone, oxycodone, and tramadol), but not necessarily for all comparisons or outcomes. No comparative analyses were possible because there was no consistent placebo or active control. Cohort outcomes for opioids are therefore reported, as absolute numbers or percentages, or both.Reviews on buprenorphine, codeine with or without paracetamol, hydromorphone, methadone, tramadol with or without paracetamol, tapentadol, and oxycodone did not have information about the primary outcome of mild or no pain at 14 days, although that on oxycodone indicated that average pain scores were within that range. Two reviews, on oral morphine and transdermal fentanyl, reported that 96% of 850 participants achieved that goal.Adverse event withdrawal was reported by five reviews, at rates of between 6% and 19%. Participants with at least one adverse event were reported by three reviews, at rates of between 11% and 77%.Our GRADE assessment of evidence quality was very low for all outcomes, because many studies in the reviews were at high risk of bias from several sources, including small study size.

AUTHORS' CONCLUSIONS

The amount and quality of evidence around the use of opioids for treating cancer pain is disappointingly low, although the evidence we have indicates that around 19 out of 20 people with moderate or severe pain who are given opioids and can tolerate them should have that pain reduced to mild or no pain within 14 days. This accords with the clinical experience in treating many people with cancer pain, but overstates to some extent the effectiveness found for the WHO pain ladder. Most people will experience adverse events, and help may be needed to manage the more common undesirable adverse effects such as constipation and nausea. Perhaps between 1 in 10 and 2 in 10 people treated with opioids will find these adverse events intolerable, leading to a change in treatment.

Gabapentin for chronic neuropathic pain in adults

BACKGROUND

Gabapentin is commonly used to treat neuropathic pain (pain due to nerve damage). This review updates a review published in 2014, and previous reviews published in 2011, 2005 and 2000.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of gabapentin in chronic neuropathic pain in adults.

SEARCH METHODS

For this update we searched CENTRAL), MEDLINE, and Embase for randomised controlled trials from January 2014 to January 2017. We also searched the reference lists of retrieved studies and reviews, and online clinical trials registries.

SELECTION CRITERIA

We included randomised, double-blind trials of two weeks' duration or longer, comparing gabapentin (any route of administration) with placebo or another active treatment for neuropathic pain, with participant-reported pain assessment.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality and potential bias. Primary outcomes were participants with substantial pain relief (at least 50% pain relief over baseline or very much improved on Patient Global Impression of Change scale (PGIC)), or moderate pain relief (at least 30% pain relief over baseline or much or very much improved on PGIC). We performed a pooled analysis for any substantial or moderate benefit. Where pooled analysis was possible, we used dichotomous data to calculate risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) or harmful outcome (NNH). We assessed the quality of the evidence using GRADE and created 'Summary of findings' tables.

MAIN RESULTS

We included four new studies (530 participants), and excluded three previously included studies (126 participants). In all, 37 studies provided information on 5914 participants. Most studies used oral gabapentin or gabapentin encarbil at doses of 1200 mg or more daily in different neuropathic pain conditions, predominantly postherpetic neuralgia and painful diabetic neuropathy. Study duration was typically four to 12 weeks. Not all studies reported important outcomes of interest. High risk of bias occurred mainly due to small size (especially in cross-over studies), and handling of data after study withdrawal.In postherpetic neuralgia, more participants (32%) had substantial benefit (at least 50% pain relief or PGIC very much improved) with gabapentin at 1200 mg daily or greater than with placebo (17%) (RR 1.8 (95% CI 1.5 to 2.1); NNT 6.7 (5.4 to 8.7); 8 studies, 2260 participants, moderate-quality evidence). More participants (46%) had moderate benefit (at least 30% pain relief or PGIC much or very much improved) with gabapentin at 1200 mg daily or greater than with placebo (25%) (RR 1.8 (95% CI 1.6 to 2.0); NNT 4.8 (4.1 to 6.0); 8 studies, 2260 participants, moderate-quality evidence).In painful diabetic neuropathy, more participants (38%) had substantial benefit (at least 50% pain relief or PGIC very much improved) with gabapentin at 1200 mg daily or greater than with placebo (21%) (RR 1.9 (95% CI 1.5 to 2.3); NNT 5.9 (4.6 to 8.3); 6 studies, 1277 participants, moderate-quality evidence). More participants (52%) had moderate benefit (at least 30% pain relief or PGIC much or very much improved) with gabapentin at 1200 mg daily or greater than with placebo (37%) (RR 1.4 (95% CI 1.3 to 1.6); NNT 6.6 (4.9 to 9.9); 7 studies, 1439 participants, moderate-quality evidence).For all conditions combined, adverse event withdrawals were more common with gabapentin (11%) than with placebo (8.2%) (RR 1.4 (95% CI 1.1 to 1.7); NNH 30 (20 to 65); 22 studies, 4346 participants, high-quality evidence). Serious adverse events were no more common with gabapentin (3.2%) than with placebo (2.8%) (RR 1.2 (95% CI 0.8 to 1.7); 19 studies, 3948 participants, moderate-quality evidence); there were eight deaths (very low-quality evidence). Participants experiencing at least one adverse event were more common with gabapentin (63%) than with placebo (49%) (RR 1.3 (95% CI 1.2 to 1.4); NNH 7.5 (6.1 to 9.6); 18 studies, 4279 participants, moderate-quality evidence). Individual adverse events occurred significantly more often with gabapentin. Participants taking gabapentin experienced dizziness (19%), somnolence (14%), peripheral oedema (7%), and gait disturbance (14%).

AUTHORS' CONCLUSIONS

Gabapentin at doses of 1800 mg to 3600 mg daily (1200 mg to 3600 mg gabapentin encarbil) can provide good levels of pain relief to some people with postherpetic neuralgia and peripheral diabetic neuropathy. Evidence for other types of neuropathic pain is very limited. The outcome of at least 50% pain intensity reduction is regarded as a useful outcome of treatment by patients, and the achievement of this degree of pain relief is associated with important beneficial effects on sleep interference, fatigue, and depression, as well as quality of life, function, and work. Around 3 or 4 out of 10 participants achieved this degree of pain relief with gabapentin, compared with 1 or 2 out of 10 for placebo. Over half of those treated with gabapentin will not have worthwhile pain relief but may experience adverse events. Conclusions have not changed since the previous update of this review.

Tramadol with or without paracetamol (acetaminophen) for cancer pain

BACKGROUND

Tramadol is an opioid analgesic licensed for use in moderate to severe pain. It is considered as a low risk for abuse, so control regulations are not as stringent as for 'strong' opioids such as morphine. It has a potential role as a step 2 option of the World Health Organization (WHO) analgesic ladder.

OBJECTIVES

To assess the benefits and adverse effects of tramadol with or without paracetamol (acetaminophen) for cancer-related pain.

SEARCH METHODS

We searched the following databases using a wide range of search terms: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and LILACS. We also searched three clinical trials registry databases. The date of the last search was 2 November 2016.

SELECTION CRITERIA

We selected studies that were randomised, with placebo or active controls, or both, and included a minimum of 10 participants per treatment arm. We were interested particularly in blinded studies, but also included open studies.We excluded non-randomised studies, studies of experimental pain, case reports, and clinical observations.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data using a standard form and checked for agreement before entry into Review Manager 5. We included information about the number of participants treated and demographic details, type of cancer, drug and dosing regimen, study design (placebo or active control) and methods, study duration and follow-up, analgesic outcome measures and results, withdrawals, and adverse events. We collated multiple reports of the same study, so that each study, rather than each report, was the unit of interest in the review. We assessed the evidence using GRADE and created a 'Summary of findings' table.The main outcomes of interest for benefit were pain reduction of 30% or greater and 50% or greater from baseline, participants with pain no worse than mild, and participants feeling much improved or very much improved.

MAIN RESULTS

We included 10 studies (12 reports) with 958 adult participants. All the studies enrolled participants with chronic malignant tumour-related pain who were experiencing pain intensities described as moderate to severe, with most experiencing at least 4/10 with current treatment. The mean ages were 59 to 70 years, with participants aged between 24 and 87 years. Study length ranged from one day to six months. Five studies used a cross-over design. Tramadol doses ranged from 50 mg as single dose to 600 mg per day; doses of 300 mg per day to 400 mg per day were most common.Nine studies were at high risk of bias for one to four criteria (only one high risk of bias for size). We judged all the results to be very low quality evidence because of widespread lack of blinding of outcome assessment, inadequately described sequence generation, allocation concealment, and small numbers of participants and events. Important outcomes were poorly reported. There were eight different active comparators and one comparison with placebo. There was little information available for any comparison and no firm conclusions could be drawn for any outcome.Single comparisons of oral tramadol with codeine plus paracetamol, of dihydrocodeine, and of rectal versus oral tramadol provided no data for key outcomes. One study used tramadol combined with paracetamol; four participants received this intervention. One study compared tramadol with flupirtine - a drug that is no longer available. One study compared tramadol with placebo and a combination of cobrotoxin, tramadol, and ibuprofen, but the dosing schedule poorly explained.Two studies (191 participants) compared tramadol with buprenorphine. One study (131 participants) reported a similar proportion of no or mild pain at 14 days.Three studies (300 participants) compared tramadol with morphine. Only one study, combining tramadol, tramadol plus paracetamol, and paracetamol plus codeine as a single weak-opioid group reported results. Weak opioid produced reduction in pain of at least 30% from baseline in 55/117 (47%) participants, compared with 91/110 (82%) participants with morphine. Weak opioid produced reduction in pain of at least 50% in 49/117 (42%) participants, compared with 83/110 (75%) participants with morphine.There was no useful information for any other outcome of benefit or harm.

AUTHORS' CONCLUSIONS

There is limited, very low quality, evidence from randomised controlled trials that tramadol produced pain relief in some adults with pain due to cancer and no evidence at all for children. There is very low quality evidence that it is not as effective as morphine. This review does not provide a reliable indication of the likely effect. The likelihood that the effect will be substantially different is very high. The place of tramadol in managing cancer pain and its role as step 2 of the WHO analgesic ladder is unclear.