Graphical augmentations to the funnel plot assess the impact of additional evidence on a meta-analysis

Akkermansia muciniphila for the Prevention of Type 2 Diabetes and Obesity: A Meta-Analysis of Animal Studies

BACKGROUND

More than half of the states in the U.S. report that over 30% of adults are obese. Obesity increases the risk of many chronic diseases, including type 2 diabetes, hypertension, and cardiovascular disease, and can even reduce one's lifespan. Similarly, the prevalence of type 2 diabetes follows a comparable trend. As a result, researchers are striving to find solutions to reduce obesity rates, with a particular focus on gut health, which has been previously linked to both obesity and type 2 diabetes. Recent studies suggest that Akkermansia muciniphila (Akk) may have a positive probiotic effect on preventing the onset of type 2 diabetes and obesity.

METHODS

We conducted a quantitative meta-analysis of 15 qualified animal studies investigating the effects of Akk administration as a probiotic.

RESULTS

The statistical analyses showed that Akk administration significantly reduced body weight gain by 10.4% and fasting blood glucose by 21.2%, while also significantly improving glucose tolerance by 22.1% and increasing blood insulin levels by 26.9%. However, our analysis revealed substantial heterogeneity between the control and experimental groups across all subgroups.

CONCLUSIONS

Overall, Akk appears to be effective at reducing the onset of type 2 diabetes and diet-induced obesity. Long-term studies with larger sample sizes are needed to confirm these beneficial effects, as the current animal studies were of short duration (less than 20 weeks).

The Role of Exercise in Statin-Associated Muscle Symptoms Outcomes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

To provide a synthesis of randomized controlled trials (RCTs) investigating statin-associated muscle symptoms (SAMS) in adults who underwent exercise training intervention.

Patients and Methods

We systematically searched 5 electronic databases for placebo-controlled RCTs through January 31, 2023. We included short-term and long-term exercise interventions that compared the efficacy and safety of exercise+statin vs exercise+placebo in healthy adults and reported SAMS preintervention and postintervention. Publication bias and methodological study quality assessments were performed.

Results

Five of 454 potentially qualifying RCTs met the inclusion criteria, all short-term exercise RCTs. Participants were predominantly physically inactive young to middle-aged (M=37.2 y) men (57%), 252 (49%) who were on statin therapy, and 271 (53%) on placebo. Of the 3 RCTs providing qualitative SAMS results, 19 (9%) out of 220 participants reported SAMS on exercise+statin and 10 (4%) out of 234 reported SAMS on exercise+placebo. There was no difference between exercise+statin vs exercise+placebo for maximal oxygen consumption (d=-0.18; 95% CI, -0.37 to 0.00; P=.06) or creatine kinase after short-term exercise (d=0.59; 95% CI, -0.06 to 1.25; P=.08). Participants in the exercise+statin group reduced low-density lipoprotein cholesterol vs exercise+placebo (d=-1.84; 95% CI, -2.28 to -1.39; P<.001). Most of the RCTs exhibited low levels of risk of bias (k=4, 80%) and achieved moderate methodological study quality (75.0%±5.2%).

Conclusion

Self-reported SAMs tended to be 5% greater after short-term exercise in statin users compared with placebo, although this difference did not achieve statistical significance. There remains an important need for placebo-controlled RCTs investigating the prevalence of statin-induced SAMS during exercise training.

The impact of theatre on social competencies: a meta-analytic evaluation

BACKGROUND

There has been agrowing interest in using artistic interventions as a method of developing interpersonal competence. This paper presents a meta-analysis evaluating the impact of theatre interventions on social competencies.

METHODS

Twenty-one primary studies totaling 4064 participants were included, presenting evidence available since 1983. Included studies were assessed in terms of quality, heterogeneity, and publication bias.

RESULTS

Our findings indicated that active theatre participation significantly improved participants' empathic abilities, social communication, tolerance, and social interactions, with the largest pooled effect size for social communication (0.698) and the smallest for tolerance (0.156). Our findings did not corroborate the impact of theatre on self-concept.

CONCLUSIONS

This paper shows that theatre interventions have a positive impact on social competencies. The paper makes a methodological contribution by showing that randomized and non-randomized studies yielded comparably valid results.

Effect of exercise therapy in patients with hip osteoarthritis: A systematic review and cumulative meta-analysis

Objective

To evaluate the existing evidence on the effect of exercise therapy in patients with hip osteoarthritis (OA) compared to no treatment and explore whether a further trial will change the current evidence.

Design

Systematic review and cumulative meta-analysis using randomized controlled trials (RCT) to determine the effect on pain and function post-treatment, and at 6-9 months after treatment. Standardized mean difference (SMD) ​≤ ​-0.37 was considered clinically worthwhile. Extended funnel plots were used to simulate the impact of a new trial on the pooled effect size of pain and function.

Results

18 RCTs were included. Post-treatment we found a beneficial effect of exercise therapy on pain (SMD -0.38, 95% Confidence Interval (CI): 0.55 to -0.22) and function (SMD -0.31, 95% CI -0.49 to -0.11). A beneficial effect of exercise therapy on pain (SMD -0.23, 95% CI: 0.41 to -0.05) and function (SMD -0.29, 95% CI: 0.45 to -0.12) was found 6-9 months after treatment. Most effect estimates were small, and it is unclear whether these are clinically meaningful. Extended funnel plots and a simulation of a new trial showed that only a new trial with a larger effect than the current pooled effect or a trial including 74,843 participants would change the pooled effect estimate from an unclear to a clearly clinically worthwhile effect.

Conclusions

We found a beneficial effect of exercise therapy on pain and function in hip OA. It is unlikely a new trial added to current evidence will change the conclusion.

Hand-assisted versus straight laparoscopy for colorectal surgery - a systematic review and meta-analysis

PURPOSE

Hand-assisted laparoscopic surgery (HALS) is an alternative to straight laparoscopy (LAP) in colorectal surgery. Many studies have compared the two in terms of efficacy, complications, and outcomes. This meta-analysis aims to uncover if there are any significant differences in conversion rates, operative times, body mass index (BMI), incision lengths, intraoperative and postoperative complications, and length of stay.

METHODS

Comprehensive searches were performed on databases from their respective inceptions to 16 December 2021, with a manual search performed through Scopus. Randomized controlled trials (RCTs), cohort studies, and case series involving more than 10 patients were included.

RESULTS

A total of 47 studies were found fitting the inclusion criteria, with 5 RCTs, 41 cohort studies, and 1 case series. Hand-assisted laparoscopic surgery was associated with lower conversion rates (odds ratio [OR] 0.41, 95%CI 0.28-0.60, p < 0.00001), shorter operative times (Mean Difference [MD] - 8.32 min, 95%CI - 14.05- - 2.59, p = 0.004), and higher BMI (MD 0.79, 95%CI 0.46-1.13, p < 0.00001), but it was also associated with longer incision lengths (MD 2.19 cm, 95%CI 1.66-2.73 cm, p < 0.00001), and higher postoperative complication rates (OR 1.15, 95%CI 1.06-1.24, p = 0.0004). Length of stay was not different in HALS as compared to Lap (MD 0.16 days, 95%CI - 0.06-0.38 days, p = 0.16, and intraoperative complications were the same between both techniques.

CONCLUSIONS

Hand-assisted laparoscopy is a suitable alternative to straight laparoscopy with benefits and risks. While there are many cohort studies comparing HALS and LAP, more RCTs would be needed for a better quality of evidence.

Evaluation of comprehensive benefits of sponge cities using meta-analysis in different geographical environments in China

With the rapid progress in urbanization, frequent urban waterlogging and non-point source pollution are threatening the living and health of human beings. Sponge city construction has become an effective means to curb urban waterlogging. Although related studies have explored the comprehensive benefits of sponge cities, few studies have been conducted on the effects of different geographical environments on runoff control and suspended solid (SS) removal. Based on 76 cities with sponge cities in China, this study used the meta-analysis method to evaluate the relationships of climate, terrain, underlying surface conditions, and construction area with the increase in the total annual runoff control rate and SS removal rate. The results reveal that the runoff control benefit can be significantly improved by sponge cities under the combined conditions of average annual precipitation of approximately 1000 mm, high fractional vegetation cover, sufficient soil fertility, a terrain slope i of ≤2%, and a permeability coefficient of strata of 100-200 m/d, especially in northern China, where the weight representing the quantity of comprehensive benefits was calculated to be 25.5%. In addition, the study results assist in reforming unfavorable geographical environments in the construction of sponge city, thus providing more effective solutions for tackling SS pollution. The most significant benefits of SS removal were obtained in north central China, where the weight was 21.4%. This study comprehensively investigated the effects of geographical environmental factors on the comprehensive benefits of sponge city reflected by the improvement in the total annual runoff control rate and the SS removal rate. The results will provide guidance for the planning and design of global sponge cities and effectively optimize the practice, scale, and location of existing construction based on specific geographical environments.

Diagnostic Value of Serum Chitinase-3-Like Protein 1 for Liver Fibrosis: A Meta-analysis

Background

Serum chitinase-3-like protein 1 (CHI3L1) is a promising marker for diagnosing liver fibrosis. This meta-analysis was carried out to assess the diagnostic performance of serum CHI3L1 for the estimation of liver fibrosis.

Methods

Systematic searches were performed on PubMed, Embase, Web of Science, Scopus, the Cochrane Library, Google Scholar, Sinomed, the China National Knowledge Infrastructure (CNKI), the Chinese Medical Journal Database, and the Wanfang databases for available studies. The primary studies were screened strictly according to inclusion and exclusion criteria, and sensitivity, specificity, and other measures of accuracy of serum CHI3L1 for evaluating liver fibrosis were pooled with 95% confidence intervals. I² was calculated to assess heterogeneity, and sources of heterogeneity were explored by subgroup analysis. Deeks' test was used to assess for publication bias, and likelihood ratio was used to determine posttest probability.

Results

Our research integrated 11 articles, accounting for 1897 patients older than 18 years old. The pooled sensitivity and specificity for significant fibrosis, advanced fibrosis, and cirrhosis were 0.79 and 0.82 with an area under the receiver operating characteristic curve (AUC) of 0.85, 0.81 and 0.83 with an AUC of 0.91, and 0.72 and 0.74 with an AUC of 0.85, respectively. Random-effects models were used to assess for significant heterogeneity, and subgroup analysis showed that age and aetiology of included patients were likely sources of heterogeneity. No potential publication bias was found for serum CHI3L1 in the diagnosis of significant fibrosis, advanced fibrosis, or cirrhosis, and posttest probability was moderate.

Conclusion

Measurement of serum CHI3L1 is a feasible diagnostic tool for liver fibrosis.

Efficacy of Transversus Abdominis Plane Block in the Reduction of Pain and Opioid Requirement in Laparoscopic and Robot-assisted Hysterectomy: A Systematic Review and Meta-analysis

OBJECTIVE

 To summarize the available evidence of TAP Block in efficacy in laparoscopic or robotic hysterectomy.

DATA SOURCES

 We searched databases and gray literature for randomized controlled trials in which transversus abdominis plane (TAP) block was compared with placebo or with no treatment in patients who underwent laparoscopic or robot-assisted hysterectomy.

METHOD OF STUDY SELECTION

 Two researchers independently evaluated the eligibility of the selected articles.

TABULATION, INTEGRATION, AND RESULTS

 Seven studies were selected, involving 518 patients. Early postoperative pain showed a difference in the mean mean difference (MD): - 1.17 (95% confidence interval [CI]: - 1.87-0.46) in pain scale scores (I² = 68%), which was statistically significant in favor of using TAP block, but without clinical relevance; late postoperative pain: DM 0.001 (95%CI: - 0.43-0.44; I² = 69%); opioid requirement: DM 0.36 (95%CI: - 0.94-1.68; I² = 80%); and incidence of nausea and vomiting with a difference of 95%CI = - 0.11 (- 0.215-0.006) in favor of TAP.

CONCLUSION

 With moderate strength of evidence, due to the high heterogeneity and imbalance in baseline characteristics among studies, the results indicate that TAP block should not be considered as a clinically relevant analgesic technique to improve postoperative pain in laparoscopic or robotic hysterectomy, despite statistical significance in early postoperative pain scale scores.

CLINICAL TRIAL NUMBER AND REGISTRY

 PROSPERO ID - CRD42018103573.

Risk of incident atrial fibrillation with low-to-moderate alcohol consumption is associated with gender, region, alcohol category: a systematic review and meta-analysis

AIMS 

The association between low-to-moderate alcohol consumption and atrial fibrillation (AF) has yet to be fully elucidated. The main purpose of this meta-analysis was to estimate the risk of incident AF related to low-to-moderate alcohol consumption.

METHODS AND RESULTS 

A meta-analysis was performed on 13 publications discussing the estimated risk for AF with habitual low-to-moderate alcohol intake in 10 266 315 participants. Graphical augmentations to the funnel plots were used to illustrate the potential impact of additional evidence on the current meta-analysis. Thirteen eligible studies were included in this meta-analysis. We found that moderate alcohol consumption was associated with an increased risk of incident AF in males [hazard ratio (HR) 1.09, 95% confidence interval (CI): 1.07-1.11, P < 0.00001], Europeans (HR 1.32, 95% CI: 1.23-1.42, P < 0.00001), and Asians (HR 1.09, 95% CI: 1.07-1.11, P < 0.00001). Moderate beer consumption was associated with an increased risk of developing AF (HR 1.11, 95% CI: 1.02-1.21, P = 0.01). Low alcohol consumption conferred an increased risk of AF in males (HR 1.14, 95% CI: 1.01-1.28, P = 0.04) and Europeans (HR 1.12, 95% CI: 1.07-1.17, P < 0.00001).

CONCLUSIONS 

This analysis represents the increased risk of incident AF in males, Europeans, and Asians at moderate alcohol consumption levels and in males and Europeans at low alcohol consumption levels. Those who drink any preferred alcohol beverage at moderate levels should be cautious for incident AF. More studies are warranted to find those factors that influence alcohol's effect on predisposing AF.

Targeting Neurotrophic Factors for Low Back Pain and Sciatica: A Systematic Review and Meta-analysis

OBJECTIVES

This meta-analysis aims to investigate the efficacy and safety of medicines that target neurotrophic factors for low back pain (LBP) or sciatica.

METHODS

We searched published and trial registry reports of randomised controlled trials evaluating the effect of medicines that target neurotrophic factors to LBP or sciatica in seven databases from inception to December 2020. Two reviewers independently identified studies, extracted data, and assessed the risk of bias and certainty in the evidence.

RESULTS

Nine studies (3349 participants) were included in the meta-analyses. Low certainty evidence showed that anti-NGF may reduce pain at four weeks (MD -6.63, 95% CI -8.51 to -4.76), and 12 weeks (MD -6.10, -8.34 to -3.87), and may increase adverse effects for chronic LBP (OR 1.16, 0.99-1.36). Higher doses of anti-NGF may offer a clinically important reduction in pain at the cost of increased adverse effects for chronic LBP. Very low certainty evidence showed that anti-NGF and glial cell line-derived neurotrophic factor (pro-GDNF) may not reduce pain for sciatica at four weeks (MD -1.40, -8.26-5.46), at 12 weeks (MD -2.91, -13.69-7.67), and may increase adverse effects for sciatica (OR 3.27, 1.78-6.00).

CONCLUSION

Anti-NGF may offer small reductions in pain intensity for chronic LBP. The effect may depend on the dose and types of medicines. For sciatica, anti-NGF or pro-GDNF may not reduce pain. Medicines that target neurotrophic factors for LBP or sciatica are associated with different adverse effects from commonly prescribed medicines for these conditions.

Probiotics for the Prevention of Antibiotic-associated Diarrhea in Adults: A Meta-Analysis of Randomized Placebo-Controlled Trials

OBJECTIVE

This meta-analysis aims to combine the latest research evidence to assess the effect of probiotics on preventing antibiotic-associated diarrhea (AAD) in adults.

METHODS

PubMed, Cochrane Library, EMBASE, and Web of Science were searched for randomized placebo-controlled trials on probiotics preventing AAD. A random or fixed effect model was used to combine the incidence of AAD (primary outcome) and the adverse event rates. The authors performed subgroup analyses to explore the effects of different participants population, probiotics species, and dosage.

RESULTS

Thirty-six studies were included with 9312 participants. Probiotics reduced the incidence of AAD by 38% (pooled relative risk, 0.62; 95% confidence interval, 0.51-0.74). The protective effect of probiotics was still significant when grouped by reasons for antibiotics treatment, probiotic duration, probiotic dosage, and time from antibiotic to probiotic. However, there were no statistically significant increased adverse events in the probiotics group (relative risk, 1.00; 95% confidence interval, 0.87-1.14).

CONCLUSIONS

This updated meta-analysis suggested that using probiotics as early as possible during antibiotic therapy has a positive and safe effect on preventing AAD in adults. Further studies should focus on the optimal dosage and duration of probiotics to develop a specific recommendation.

Conditional power of antidepressant network meta-analysis

BACKGROUND

Conditional power of network meta-analysis (NMA) can support the planning of randomized controlled trials (RCTs) assessing medical interventions. Conditional power is the probability that updating existing inconclusive evidence in NMA with additional trial(s) will result in conclusive evidence, given assumptions regarding trial design, anticipated effect sizes, or event probabilities.

METHODS

The present work aimed to estimate conditional power for potential future trials on antidepressant treatments. Existing evidence was based on a published network of 502 RCTs conducted between 1979-2018 assessing acute antidepressant treatment in major depressive disorder (MDD). Primary outcomes were efficacy in terms of the symptom change on the Hamilton Depression Scale (HAMD) and tolerability in terms of the dropout rate due to adverse events. The network compares 21 antidepressants consisting of 231 relative treatment comparisons, 164 (efficacy) and 127 (tolerability) of which are currently assumed to have inconclusive evidence.

RESULTS

Required sample sizes to achieve new conclusive evidence with at least 80% conditional power were estimated to range between N = 894 - 4190 (efficacy) and N = 521 - 1246 (tolerability). Otherwise, sample sizes ranging between N = 49 - 485 (efficacy) and N = 40 - 320 (tolerability) may require stopping for futility based on a boundary at 20% conditional power. Optimizing trial designs by considering multiple trials that contribute both direct and indirect evidence, anticipating alternative effect sizes or alternative event probabilities, may increase conditional power but required sample sizes remain high. Antidepressants having the greatest conditional power associated with smallest required sample sizes were identified as those on which current evidence is low, i.e., clomipramine, levomilnacipran, milnacipran, nefazodone, and vilazodone, with respect to both outcomes.

CONCLUSIONS

The present results suggest that conditional power to achieve new conclusive evidence in ongoing or future trials on antidepressant treatments is low. Limiting the use of the presented conditional power analysis are primarily due to the estimated large sample sizes which would be required in future trials as well as due to the well-known small effect sizes in antidepressant treatments. These findings may inform researchers and decision-makers regarding the clinical relevance and justification of research in ongoing or future antidepressant RCTs in MDD.

Efficacy, acceptability, and safety of antidepressants for low back pain: a systematic review and meta-analysis

BACKGROUND

Antidepressant medicines are used to manage symptoms of low back pain. The efficacy, acceptability, and safety of antidepressant medicines for low back pain (LBP) are not clear. We aimed to evaluate the efficacy, acceptability, and safety of antidepressant medicines for LBP.

METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov , the EU Clinical Trials Register, and the WHO International Clinical Trial Registry Platform from inception to May 2020. We included published and trial registry reports of RCTs that allocated adult participants with LBP to receive an antidepressant medicine or a placebo medicine. Pairs of authors independently extracted data in duplicate. We extracted participant characteristics, study sample size, outcome values, and measures of variance for each outcome. We data using random-effects meta-analysis models and calculated estimates of effects and heterogeneity for each outcome. We formed judgments of confidence in the evidence in accordance with GRADE. We report our findings in accordance with the PRISMA statement. We prespecified all outcomes in a prospectively registered protocol. The primary outcomes were pain intensity and acceptability. We measured pain intensity at end-of-treatment on a 0-100 point scale and considered 10 points the minimal clinically important difference. We defined acceptability as the odds of stopping treatment for any reason.

RESULTS

We included 23 RCTs in this review. Data were available for pain in 17 trials and acceptability in 14 trials. Treatment with antidepressants decreased pain intensity by 4.33  points (95% CI - 6.15 to - 2.50) on a 0-100 scale, compared to placebo. Treatment with antidepressants increased the odds of stopping treatment for any reason (OR 1.27 [95% CI 1.03 to 1.56]), compared to placebo.

CONCLUSIONS

Treatment of LBP with antidepressants is associated with small reductions in pain intensity and increased odds of stopping treatment for any reason, compared to placebo. The effect on pain is not clinically important. The effect on acceptability warrants consideration. These findings provide Level I evidence to guide clinicians in their use of antidepressants to treat LBP.

TRIAL REGISTRATION

We prospectively registered the protocol for this systematic review on PROSPERO ( CRD42020149275 ).

Efficacy and Safety of Medicines Targeting Neurotrophic Factors in the Management of Low Back Pain: Protocol for a Systematic Review and Meta-analysis

BACKGROUND

Low back pain (LBP) is the leading cause of years lived with disability worldwide. Most people with LBP receive the diagnosis of nonspecific LBP or sciatica. Medications are commonly prescribed but have limited analgesic effects and are associated with adverse events. A novel treatment approach is to target neurotrophins such as nerve growth factor (NGF) to reduce pain intensity. NGF inhibitors have been tested in some randomized controlled trials (RCTs) in recent years, showing promise for the treatment of chronic LBP; however, their efficacy and safety need to be evaluated to guide regulatory actions.

OBJECTIVE

The aim of this study is to evaluate the efficacy and safety of medicines targeting neurotrophins in patients with LBP and sciatica.

METHODS

In this systematic review, we will include published and unpublished records of parallel RCTs and the first phase of crossover RCTs that compare the effects of medicines targeting neurotrophins with any control group. We will search the CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, EU Clinical Trials Register, and WHO International Clinical Registry Platform databases from inception. Pairs of authors will independently screen the records for eligibility, and we will independently extract data in duplicate. We will conduct a quantitative synthesis (meta-analysis) with the studies that report sufficient data and compare the medicines of interest versus placebo. We will use random-effects models and calculate estimates of effects and heterogeneity for each outcome. We will assess the risk of bias for each study using the Cochrane Collaboration tool, and form judgments of confidence in the evidence according to GRADE recommendations. We will use the PRISMA statement to report the findings. We plan to conduct subgroup analyses by condition, type of medication, and time point. We will also assess the impact of a potential new trial on an existing meta-analysis. Data from studies that meet inclusion criteria but cannot be included in the meta-analysis will be reported narratively.

RESULTS

The protocol was registered on the Open Science Framework on May 19, 2020. As of December 2020, we have identified 1932 records.

CONCLUSIONS

This systematic review and meta-analysis will assess the evidence for the efficacy and safety of NGF inhibitors for pain in patients with nonspecific LBP and sciatica. The inclusion of new studies and unpublished data may improve the precision of the effect estimates and guide regulatory actions of the medications for LBP and sciatica.

TRIAL REGISTRATION

Open Science Framework; https://osf.io/b8adn/.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/22905.

Do the combined blood pressure effects of exercise and antihypertensive medications add up to the sum of their parts? A systematic meta-review

Objective

To compare the blood pressure (BP) effects of exercise alone (EXalone), medication alone (MEDSalone) and combined (EX+MEDScombined) among adults with hypertension.

Data sources

PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature, SPORTDiscus and the Cochrane Library.

Eligibility criteria

Randomised controlled trails (RCTs) or meta-analyses (MAs) of controlled trials that: (1) involved healthy adults>18 year with hypertension; (2) investigated exercise and BP; (3) reported preintervention and postintervention BP and (4) were published in English. RCTs had an EX+MEDScombined arm; and an EXalone arm and/or an MEDSalone arm; and MAs performed moderator analyses.

Design

A systematic network MA and meta-review with the evidence graded using the Physical Activity Guidelines for Americans Advisory Committee system.

Outcome

The BP response for EXalone, MEDSalone and EX+MEDScombined and compared with each other.

Results

Twelve RCTs qualified with 342 subjects (60% women) who were mostly physically inactive, middle-aged to older adults. There were 13 qualifying MAs with 28 468 participants (~50% women) who were mostly Caucasian or Asian. Most RCTs were aerobic (83.3%), while the MAs involved traditional (46%) and alternative (54%) exercise types. Strong evidence demonstrates EXalone, MEDSalone and EX+MEDScombined reduce BP and EX+MEDScombined elicit BP reductions less than the sum of their parts. Strong evidence indicates EX+MEDScombined potentiate the BP effects of MEDSalone. Although the evidence is stronger for alternative than traditional types of exercise, EXaloneelicits greater BP reductions than MEDSalone.

Conclusions

The combined BP effects of exercise and medications are not additive or synergistic, but when combined they bolster the antihypertensive effects of MEDSalone.

PROSPERO registration number

The protocol is registered at PROSPERO CRD42020181754.

Antidepressant treatment in patients following acute coronary syndromes: a systematic review and Bayesian meta-analysis

AIMS

The aim of this study is to investigate the effect of antidepressant therapy on mortality and cardiovascular outcomes in patients with acute coronary syndrome (ACS).

METHODS AND RESULTS

We systematically searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials and performed a Bayesian random-effects meta-analysis of randomized controlled trials that investigated antidepressant pharmacotherapy in patients following ACS. The primary outcome was all-cause mortality. Secondary outcomes were repeat hospitalizations and recurrent myocardial infarctions (MIs). Ten randomized controlled trials with a total of 1935 patients qualified for inclusion. Selective serotonin reuptake inhibitors were investigated in six, bupropion in three, and mirtazapine in one trial. Placebo was used as control in eight trials. There was no difference in all-cause mortality [odds ratio (OR) 0.97, 95% credible interval (CrI) 0.66-1.42] and recurrent MI (OR 0.64, 95% CrI 0.40-1.02) between patients receiving antidepressants compared with controls, whereas antidepressant therapy was associated with less repeat hospitalizations (OR 0.62, 95% CrI 0.40-0.94). In patients with ACS and concomitant depression, antidepressants reduced the odds of recurrent MI compared with usual care/placebo (OR 0.45, 95% CrI 0.25-0.81). Extended funnel plots suggest robustness of the observations.

CONCLUSIONS

Antidepressants in patients following ACS have no effect on mortality but reduce repeat hospitalizations; in patients with depression, there is a reduced risk of recurrent MI with antidepressant therapy.

Feasibility and advantages of endoscope-assisted parotidectomy: a systematic review and meta-analysis

The object of this paper was to explore the feasibility and advantages of endoscope-assisted parotid tumour resection. Three databases (PubMed, Web of Science, and Cochrane) were used to search for all related randomised controlled trials or controlled trials (up to November 2019). The key parameters for assessment included 'Endoscope', 'Endoscopes', 'Cancer of Parotid', and 'Parotid Cancer'. To evaluate the feasibility and advantages of endoscope-assisted resection of parotid tumours, the data for each parameter were pooled, based on patients who received endoscope-assisted surgery and those who received conventional surgery. This meta-analysis included seven studies, involving 170 patients in the endoscopy group and 270 patients in the control group. The analysis using the pooled data showed that there were no significant differences in the operating times between the two groups; however, the endoscopy group had significantly shorter incisions and less intraoperative bleeding. In addition, the patients who received endoscope-assisted surgery had lower incidences of temporary facial paralysis and Frey's syndrome after surgery. Patients in the endoscopy group had greater postoperative satisfaction. Endoscope-assisted parotid tumour resection results in only a small, concealed incision wound and fewer postoperative complications. Therefore, it is promising for the surgical treatment of parotid tumours.

WMA: Wizard System Architecture for the execution of meta-analysis: A case study applied to verify the efficacy of fluquinconazole in the control of Asian soybean rust

Meta-analysis is a probabilistic technique that combines results from several studies that approach the same topic and produce a result that sums up the whole. In the agricultural field, it is used to make empirical estimates of efficiency for the development of productivity and economic research on agriculture. Meta-analysis can be applied through software such as R, which is executed through commands, and produces results without providing user interactivity, nor does it reproduce a friendly and easy-to-understand interface. This paper presents the creation of a computer system, the WMA, which aims to simplify the execution of meta-analysis, providing a graphical interface and improves the display of the results through an interactive visualization using the Hierarchical Information Visualization Technique Bifocal Tree. For validation, the meta-analysis was applied in the agricultural area in a case study that grouped studies that used the fungicide fluquinconazole to combat the soybean rust disease, the results obtained through the application of the meta-analysis were analyzed using the WMA proposed tool.

Association of body mass index on disease activity in axial spondyloarthritis: systematic review and meta-analysis

OBJECTIVES

In axial spondyloarthritis (axSpA), higher body mass index (BMI) is associated with worse outcomes including response to biologics. Further clarity is needed on whether BMI is associated with disease activity overall, independent of treatment response. We performed a systematic review and meta-analysis to assess the association between BMI and disease activity as reported by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) or Ankylosing Spondylitis Disease Activity Score (ASDAS) in axSpA.

METHODS

We systematically searched for studies evaluating BMI and disease activity as the exposure and outcome of interest, respectively, in axSpA. Using random effects models, we estimated summary standardised mean differences (SMDs) and 95% CIs of BASDAI or ASDAS, comparing obese (BMI>30 kg/m²) or overweight/obese (BMI>25 kg/m²) individuals to those with normal BMI (18.5-24.9 kg/m²).

RESULTS

Twelve studies were included in the meta-analysis. Among all studies reporting the BASDAI at baseline, the pooled SMD of the BASDAI for those with an obese or overweight/obese BMI compared to a normal BMI was 0.38 (95% CI 0.21 to 0.55, I² =75.2%), indicating a significant association of higher BMI with higher BASDAI score. The pooled SMD of the ASDAS for those with an obese or overweight/obese BMI compared to a normal BMI was 0.40 (95% CI 0.27 to 0.54, I²=0%). Findings were robust across subgroup analyses.

CONCLUSION

These results demonstrate an association between an overweight/obese BMI and higher disease activity in studies of axSpA. Future longitudinal studies of BMI and disease activity should assess how this association changes over time.

Power-Enhanced Funnel Plots for Meta-Analysis

Abstract. Currently, dedicated graphical displays to depict study-level statistical power in the context of meta-analysis are unavailable. Here, we introduce the sunset (power-enhanced) funnel plot to visualize this relevant information for assessing the credibility, or evidential value, of a set of studies. The sunset funnel plot highlights the statistical power of primary studies to detect an underlying true effect of interest in the well-known funnel display with color-coded power regions and a second power axis. This graphical display allows meta-analysts to incorporate power considerations into classic funnel plot assessments of small-study effects. Nominally significant, but low-powered, studies might be seen as less credible and as more likely being affected by selective reporting. We exemplify the application of the sunset funnel plot with two published meta-analyses from medicine and psychology. Software to create this variation of the funnel plot is provided via a tailored R function. In conclusion, the sunset (power-enhanced) funnel plot is a novel and useful graphical display to critically examine and to present study-level power in the context of meta-analysis.

Charting the landscape of graphical displays for meta-analysis and systematic reviews: a comprehensive review, taxonomy, and feature analysis

BACKGROUND

Data-visualization methods are essential to explore and communicate meta-analytic data and results. With a large number of novel graphs proposed quite recently, a comprehensive, up-to-date overview of available graphing options for meta-analysis is unavailable.

METHODS

We applied a multi-tiered search strategy to find the meta-analytic graphs proposed and introduced so far. We checked more than 150 retrievable textbooks on research synthesis methodology cover to cover, six different software programs regularly used for meta-analysis, and the entire content of two leading journals on research synthesis. In addition, we conducted Google Scholar and Google image searches and cited-reference searches of prior reviews of the topic. Retrieved graphs were categorized into a taxonomy encompassing 11 main classes, evaluated according to 24 graph-functionality features, and individually presented and described with explanatory vignettes.

RESULTS

We ascertained more than 200 different graphs and graph variants used to visualize meta-analytic data. One half of these have accrued within the past 10 years alone. The most prevalent classes were graphs for network meta-analysis (45 displays), graphs showing combined effect(s) only (26), funnel plot-like displays (24), displays showing more than one outcome per study (19), robustness, outlier and influence diagnostics (15), study selection and p-value based displays (15), and forest plot-like displays (14). The majority of graphs (130, 62.5%) possessed a unique combination of graph features.

CONCLUSIONS

The rich and diverse set of available meta-analytic graphs offers a variety of options to display many different aspects of meta-analyses. This comprehensive overview of available graphs allows researchers to make better-informed decisions on which graphs suit their needs and therefore facilitates using the meta-analytic tool kit of graphs to its full potential. It also constitutes a roadmap for a goal-driven development of further graphical displays for research synthesis.

Do we need another trial on exercise in patients with knee osteoarthritis?: No new trials on exercise in knee OA

OBJECTIVE

We aim to investigate if we need additional trials on exercise in knee osteoarthritis (OA) to accept a certain effect size to be a 'true' effect size, and new studies are not needed anymore.

DESIGN

We performed a secondary analyses of a meta-analysis of studies on patients with knee osteoarthritis, on pain immediately post treatment. We performed five different analysis: a) we evaluated publication bias, b) we performed subgroup analysis, c) a sensitivity analysis based on the overall risk of bias (RoB) score, d) a cumulative meta-analysis and e) we developed an extended funnel plot to explore the potential impact of a new study on the summary effect estimate.

RESULTS

We included 42 studies with in total 6863 patients. The analyses showed that a) there is no clear publication bias, b) subgrouping did not affect the overall effect estimate, c) the effect estimate of exercise is more consistent (no heterogeneity) in the studies of low RoB, d) the benefit of exercise was clear since 2010 and e) the extended funnel plot suggests that an additional study has a none or very limited impact to change the current effect estimate.

CONCLUSION

Exercise is effective and clinically worthwhile in reducing pain immediately post treatment compared to no or minimal interventions in patients with knee OA and adding new data will unlikely change this conclusion.

Synthesizing existing evidence to design future trials: survey of methodologists from European institutions

BACKGROUND

'Conditional trial design' is a framework for efficiently planning new clinical trials based on a network of relevant existing trials. The framework considers whether new trials are required and how the existing evidence can be used to answer the research question and plan future research. The potential of this approach has not been fully realized.

METHODS

We conducted an online survey among trial statisticians, methodologists, and users of evidence synthesis research using referral sampling to capture opinions about the conditional trial design framework and current practices among clinical researchers. The questions included in the survey were related to the decision of whether a meta-analysis answers the research question, the optimal way to synthesize available evidence, which relates to the acceptability of network meta-analysis, and the use of evidence synthesis in the planning of new studies.

RESULTS

In total, 76 researchers completed the survey. Two out of three survey participants (65%) were willing to possibly or definitely consider using evidence synthesis to design a future clinical trial and around half of the participants would give priority to such a trial design. The median rating of the frequency of using such a trial design was 0.41 on a scale from 0 (never) to 1 (always). Major barriers to adopting conditional trial design include the current regulatory paradigm and the policies of funding agencies and sponsors.

CONCLUSIONS

Participants reported moderate interest in using evidence synthesis methods in the design of future trials. They indicated that a major paradigm shift is required before the use of network meta-analysis is regularly employed in the design of trials.

Challenges in assessing the sunscreen-melanoma association

Whether sunscreen use affects melanoma risk has been widely studied with contradictory results. To answer this question we performed a systematic review of all published studies, accounting for sources of heterogeneity and bias. We searched for original articles investigating the sunscreen-melanoma association in humans to February 28, 2018. We then used random-effects meta-analysis to combine estimates of the association, stratified by study design. Stratified meta-analysis and meta-regression were used to identify sources of heterogeneity. We included 21,069 melanoma cases from 28 studies published 1979-2018: 23 case-control (11 hospital-based, 12 population-based), 1 ecological, 3 cohort and 1 randomised controlled trial (RCT). There was marked heterogeneity across study designs and among case-control studies but adjustment for confounding by sun exposure, sunburns and phenotype systematically moved estimates toward decreased melanoma risk among sunscreen users. Ever- vs. never-use of sunscreen was inversely associated with melanoma in hospital-based case-control studies (adjusted odds ratio (OR) = 0.57, 95%confidence interval (CI) 0.37-0.87, pheterogeneity < 0.001), the ecological study (rate ratio = 0.48, 95%CI 0.35-0.66), and the RCT (hazard ratio (HR) = 0.49, 95%CI 0.24-1.01). It was not associated in population-based case-control studies (OR = 1.17, 95%CI 0.90-1.51, pheterogeneity < 0.001) and was positively associated in the cohort studies (HR = 1.27, 95%CI 1.07-1.51, pheterogeneity = 0.236). The association differed by latitude (pinteraction = 0.042), region (pinteraction = 0.008), adjustment for naevi/freckling (pinteraction = 0.035), and proportion of never-sunscreen-users (pinteraction = 0·012). Evidence from observational studies on sunscreen use and melanoma risk was weak and heterogeneous, consistent with the challenges of controlling for innate confounding by indication. The only RCT showed a protective effect of sunscreen.

The risk of conclusion change in systematic review updates can be estimated by learning from a database of published examples

OBJECTIVES

To determine which systematic review characteristics are needed to estimate the risk of conclusion change in systematic review updates.

STUDY DESIGN AND SETTING

We applied classification trees (a machine learning method) to model the risk of conclusion change in systematic review updates, using pairs of systematic reviews and their updates as samples. The classifiers were constructed using a set of features extracted from systematic reviews and the relevant trials added in published updates. Model performance was measured by recall, precision, and area under the receiver operating characteristic curve (AUC).

RESULTS

We identified 63 pairs of systematic reviews and updates, of which 20 (32%) exhibited a change in conclusion in their updates. A classifier using information about new trials exhibited the highest performance (AUC: 0.71; recall: 0.75; precision: 0.43) compared to a classifier that used fewer features (AUC: 0.65; recall: 0.75; precision: 0.39).

CONCLUSION

When estimating the risk of conclusion change in systematic review updates, information about the sizes of trials that will be added in an update are most useful. Future tools aimed at signaling conclusion change risks would benefit from complementary tools that automate screening of relevant trials.

Software engineering principles address current problems in the systematic review ecosystem

Systematic reviewers are simultaneously unable to produce systematic reviews fast enough to keep up with the availability of new trial evidence while overproducing systematic reviews that are unlikely to change practice because they are redundant or biased. Although the transparency and completeness of trial reporting has improved with changes in policy and new technologies, systematic reviews have not yet benefited from the same level of effort. We found that new methods and tools used to automate aspects of systematic review processes have focused on improving the efficiency of individual systematic reviews rather than the efficiency of the entire ecosystem of systematic review production. We use software engineering principles to review challenges and opportunities for improving the interoperability, integrity, efficiency, and maintainability. We conclude by recommending ways to improve access to structured systematic review results. Major opportunities for improving systematic reviews will come from new tools and changes in policy focused on doing the right systematic reviews rather than just doing more of them faster.

Safety and sedative effect of intranasal dexmedetomidine in mandibular third molar surgery: a systematic review and meta-analysis

Objective

The focus of this meta-analysis was to assess the sedative effect and safety of intranasal dexmedetomidine (Dex) in mandibular third molar surgery.

Methods

The PubMed/Medline, Web of Science, Cochrane Library, and China National Knowledge Infrastructure databases were searched for studies published until May 1, 2018. Eligible studies were restricted to randomized controlled trials (RCTs) and controlled clinical trials. The evaluation indicators mainly included the bispectral index, observer assessment of alertness/sedation scale, systolic blood pressure, and heart rate. Data for each period in the Dex and control groups were pooled to evaluate its sedative effect and safety.

Results

Five RCTs met the inclusion criteria. This study included 363 patients: 158 patients received intranasal inhalation of Dex before surgery, and 158 patients were negative controls. The pooled results showed a good sedative effect during tooth extraction when intranasal inhalation of Dex was performed 30 minutes before third molar extraction (assessment of alertness/sedation, Dex vs control SMD −1.20, 95% CI −1.73 to −0.67, I²=0, P=0.95; bispectral index, Dex vs control SMD −11.68, 95% CI −19.49 to −3.87, I²=89%; P=0.0001), and parameters returned to normal within 90 minutes after inhalation. During the operation, blood pressure and heart rate decreased to some extent, but the decreases did not exceed 20% of the baseline, and all patients returned to normal conditions within 90 minutes after inhalation.

Conclusion

Intranasal inhalation of Dex 30 minutes before third molar extraction can provide a good sedative effect, and large-sample multicenter RCTs are needed to evaluate the analgesic effect of Dex.

Systematic review with meta-analysis on transplantation for alcohol-related liver disease: Very low evidence of improved outcomes

BACKGROUND

Alcohol-related liver disease (ALD) is a leading cause of liver failure and indication for liver transplantation that arises in the setting of alcohol use disorder (AUD). Previous reviews of transplantation for ALD are limited in scope of outcomes and type of ALD studied. A comprehensive systematic review could improve use of transplantation in ALD and improve future research. We hypothesize that while transplanting ALD may improve mortality and relapse, findings will be limited by pre-specified causes of heterogeneity - assessment and treatment of AUD, definition of ALD, spectrum of ALD studied, assessment and rates of relapse, and study quality and bias.

AIM

To optimize liver transplantation for ALD, understanding existing research to guide future research, we conducted a systematic review with meta-analysis.

METHODS

We conducted a systematic review, comparing liver transplant to no-transplant in patients with ALD, with a primary outcome of both short- and long-term mortality and relapse. We performed a comprehensive search of MEDLINE, EMBASE, Web of Science, and The Cochrane Library databases for peer-reviewed journal articles comparing use of liver transplant in ALD to no-transplant. Two reviewers independently conducted screening, full text review, and data extraction according to the PRISMA guidelines. We report the quality of the evidence according to the GRADE criteria.

RESULTS

We analyzed data from 10 studies. Of 1332 participants, 34.2% (456/1332) had undergone liver transplantation, while 65.8% (876/1332) had not. While random effects meta-analysis suggested transplant in comparison to no-transplant had an association of reduced mortality that did not reach statistical significance, relative risk (RR) = 0.51 (0.25-1.05), but not relapse risk, RR = 0.52 (0.18-1.53), significant heterogeneity limited these findings. When restricted to prospective data, transplant compared to no-transplant significantly reduced mortality, RR = 0.25 (0.13-0.46, P < 0.01), and relapse, RR = 0.25 (0.14-0.45, P < 0.01), with insignificant heterogeneity but persistent small-study effects. The overall quality of the evidence was Very Low. Heterogeneity analysis suggested that AUD assessment and treatment was often not reported while ALD, relapse assessment and rate, and data collection were institutionally rather than standardly defined.

CONCLUSION

Systematic review of liver transplantation for ALD suggests reduced mortality and relapse in heterogeneous, institution-specific populations with inherent bias. To understand efficacy of transplanting ALD, our research approach must change.

Visual Inference for the Funnel Plot in Meta-Analysis

Abstract. The funnel plot is widely used in meta-analyses to assess potential publication bias. However, experimental evidence suggests that informal, mere visual, inspection of funnel plots is frequently prone to incorrect conclusions, and formal statistical tests (Egger regression and others) entirely focus on funnel plot asymmetry. We suggest using the visual inference framework with funnel plots routinely, including for didactic purposes. In this framework, the type I error is controlled by design, while the explorative, holistic, and open nature of visual graph inspection is preserved. Specifically, the funnel plot of the actually observed data is presented simultaneously, in a lineup, with null funnel plots showing data simulated under the null hypothesis. Only when the real data funnel plot is identifiable from all the funnel plots presented, funnel plot-based conclusions might be warranted. Software to implement visual funnel plot inference is provided via a tailored R function.

Use of a random effects meta-analysis in the design and analysis of a new clinical trial

In designing a randomized controlled trial, it has been argued that trialists should consider existing evidence about the likely intervention effect. One approach is to form a prior distribution for the intervention effect based on a meta‐analysis of previous studies and then power the trial on its ability to affect the posterior distribution in a Bayesian analysis. Alternatively, methods have been proposed to calculate the power of the trial to influence the “pooled” estimate in an updated meta‐analysis. These two approaches can give very different results if the existing evidence is heterogeneous, summarised using a random effects meta‐analysis. We argue that the random effects mean will rarely represent the trialist's target parameter, and so, it will rarely be appropriate to power a trial based on its impact upon the random effects mean. Furthermore, the random effects mean will not generally provide an appropriate prior distribution. More appropriate alternatives include the predictive distribution and shrinkage estimate for the most similar study. Consideration of the impact of the trial on the entire random effects distribution might sometimes be appropriate. We describe how beliefs about likely sources of heterogeneity have implications for how the previous evidence should be used and can have a profound impact on the expected power of the new trial. We conclude that the likely causes of heterogeneity among existing studies need careful consideration. In the absence of explanations for heterogeneity, we suggest using the predictive distribution from the meta‐analysis as the basis for a prior distribution for the intervention effect.

Systematic review of interventions for treating or preventing antipsychotic-induced tardive dyskinesia

BACKGROUND

Antipsychotic medication can cause tardive dyskinesia (TD) - late-onset, involuntary, repetitive movements, often involving the face and tongue. TD occurs in > 20% of adults taking antipsychotic medication (first-generation antipsychotics for > 3 months), with this proportion increasing by 5% per year among those who continue to use these drugs. The incidence of TD among those taking newer antipsychotics is not different from the rate in people who have used older-generation drugs in moderate doses. Studies of TD have previously been found to be limited, with no treatment approach shown to be effective.

OBJECTIVES

To summarise the clinical effectiveness and safety of treatments for TD by updating past Cochrane reviews with new evidence and improved methods; to undertake public consultation to gauge the importance of the topic for people living with TD/the risk of TD; and to make available all data from relevant trials.

DATA SOURCES

All relevant randomised controlled trials (RCTs) and observational studies.

REVIEW METHODS

Cochrane review methods, network meta-analysis (NMA).

DESIGN

Systematic reviews, patient and public involvement consultation and NMA.

SETTING

Any setting, inpatient or outpatient.

PARTICIPANTS

For systematic reviews, adults with TD who have been taking a stable antipsychotic drug dose for > 3 months.

INTERVENTIONS

Any, with emphasis on those relevant to UK NHS practice.

MAIN OUTCOME MEASURES

Any measure of TD, global assessments and adverse effects/events.

RESULTS

We included 112 studies (nine Cochrane reviews). Overall, risk of bias showed little sign of improvement over two decades. Taking the outcome of 'TD symptoms improved to a clinically important extent', we identified two trials investigating reduction of antipsychotic dose [n = 17, risk ratio (RR) 0.42, 95% confidence interval (CI) 0.17 to 1.04; very low quality]. Switching was investigated twice in trials that could not be combined (switching to risperidone vs. antipsychotic withdrawal: one RCT, n = 42, RR 0.45, 95% CI 0.23 to 0.89; low quality; switching to quetiapine vs. haloperidol: one RCT, n = 45, RR 0.80, 95% CI 0.52 to 1.22; low quality). In addition to RCTs, six observational studies compared antipsychotic discontinuation with decreased or increased dosage, and there was no clear evidence that any of these strategies had a beneficial effect on TD symptoms (very low-quality evidence). We evaluated the addition to standard antipsychotic care of several treatments, but not anticholinergic treatments, for which we identified no trials. We found no clear effect of the addition of either benzodiazepines (two RCTs, n = 32, RR 1.12, 95% CI 0.6 to 2.09; very low quality) or vitamin E (six RCTs, n = 264, RR 0.95, 95% CI 0.89 to 1.01; low quality). Buspirone as an adjunctive treatment did have some effect in one small study (n = 42, RR 0.53, 95% CI 0.33 to 0.84; low quality), as did hypnosis and relaxation (one RCT, n = 15, RR 0.45, 95% CI 0.21 to 0.94; very low quality). We identified no studies focusing on TD in people with dementia. The NMA model found indirect estimates to be imprecise and failed to produce useful summaries on relative effects of interventions or interpretable results for decision-making. Consultation with people with/at risk of TD highlighted that management of TD remains a concern, and found that people are deeply disappointed at the length of time it has taken researchers to address the issue.

LIMITATIONS

Most studies remain small and poorly reported.

CONCLUSIONS

Clinicians, policy-makers and people with/at risk of TD are little better informed than they were decades ago. Underpowered trials of limited quality repeatedly fail to provide answers.

FUTURE WORK

TD reviews have data from current trials extracted, tabulated and traceable to source. The NMA highlights one context in which support for this technique is ill advised. All relevant trials, even if not primarily addressing the issue of TD, should report appropriate binary outcomes on groups of people with this problem. Randomised trials of treatments for people with established TD are indicated. These should be large (> 800 participants), necessitating accrual through accurate local/national registers, including an intervention with acceptable treatments and recording outcomes used in clinical practice.

STUDY REGISTRATION

This study is registered as PROSPERO CRD4201502045.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children

BACKGROUND

Antibiotics can disturb gastrointestinal microbiota which may lead to reduced resistance to pathogens such as Clostridium difficile (C. difficile). Probiotics are live microbial preparations that, when administered in adequate amounts, may confer a health benefit to the host, and are a potential C. difficile prevention strategy. Recent clinical practice guidelines do not recommend probiotic prophylaxis, even though probiotics have the highest quality evidence among cited prophylactic therapies.

OBJECTIVES

To assess the efficacy and safety of probiotics for preventing C.difficile-associated diarrhea (CDAD) in adults and children.

SEARCH METHODS

We searched PubMed, EMBASE, CENTRAL, and the Cochrane IBD Group Specialized Register from inception to 21 March 2017. Additionally, we conducted an extensive grey literature search.

SELECTION CRITERIA

Randomized controlled (placebo, alternative prophylaxis, or no treatment control) trials investigating probiotics (any strain, any dose) for prevention of CDAD, or C. difficile infection were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors (independently and in duplicate) extracted data and assessed risk of bias. The primary outcome was the incidence of CDAD. Secondary outcomes included detection of C. difficile infection in stool, adverse events, antibiotic-associated diarrhea (AAD) and length of hospital stay. Dichotomous outcomes (e.g. incidence of CDAD) were pooled using a random-effects model to calculate the risk ratio (RR) and corresponding 95% confidence interval (95% CI). We calculated the number needed to treat for an additional beneficial outcome (NNTB) where appropriate. Continuous outcomes (e.g. length of hospital stay) were pooled using a random-effects model to calculate the mean difference and corresponding 95% CI. Sensitivity analyses were conducted to explore the impact of missing data on efficacy and safety outcomes. For the sensitivity analyses, we assumed that the event rate for those participants in the control group who had missing data was the same as the event rate for those participants in the control group who were successfully followed. For the probiotic group, we calculated effects using the following assumed ratios of event rates in those with missing data in comparison to those successfully followed: 1.5:1, 2:1, 3:1, and 5:1. To explore possible explanations for heterogeneity, a priori subgroup analyses were conducted on probiotic species, dose, adult versus pediatric population, and risk of bias as well as a post hoc subgroup analysis on baseline risk of CDAD (low 0% to 2%; moderate 3% to 5%; high > 5%). The overall quality of the evidence supporting each outcome was independently assessed using the GRADE criteria.

MAIN RESULTS

Thirty-nine studies (9955 participants) met the eligibility requirements for our review. Overall, 27 studies were rated as either high or unclear risk of bias. A complete case analysis (i.e. participants who completed the study) among trials investigating CDAD (31 trials, 8672 participants) suggests that probiotics reduce the risk of CDAD by 60%. The incidence of CDAD was 1.5% (70/4525) in the probiotic group compared to 4.0% (164/4147) in the placebo or no treatment control group (RR 0.40, 95% CI 0.30 to 0.52; GRADE = moderate). Twenty-two of 31 trials had missing CDAD data ranging from 2% to 45%. Our complete case CDAD results proved robust to sensitivity analyses of plausible and worst-plausible assumptions regarding missing outcome data and results were similar whether considering subgroups of trials in adults versus children, inpatients versus outpatients, different probiotic species, lower versus higher doses of probiotics, or studies at high versus low risk of bias. However, in a post hoc analysis, we did observe a subgroup effect with respect to baseline risk of developing CDAD. Trials with a baseline CDAD risk of 0% to 2% and 3% to 5% did not show any difference in risk but trials enrolling participants with a baseline risk of > 5% for developing CDAD demonstrated a large 70% risk reduction (interaction P value = 0.01). Among studies with a baseline risk > 5%, the incidence of CDAD in the probiotic group was 3.1% (43/1370) compared to 11.6% (126/1084) in the control group (13 trials, 2454 participants; RR 0.30, 95% CI 0.21 to 0.42; GRADE = moderate). With respect to detection of C. difficile in the stool pooled complete case results from 15 trials (1214 participants) did not show a reduction in infection rates. C. difficile infection was 15.5% (98/633) in the probiotics group compared to 17.0% (99/581) in the placebo or no treatment control group (RR 0.86, 95% CI 0.67 to 1.10; GRADE = moderate). Adverse events were assessed in 32 studies (8305 participants) and our pooled complete case analysis indicates probiotics reduce the risk of adverse events by 17% (RR 0.83, 95% CI 0.71 to 0.97; GRADE = very low). In both treatment and control groups the most common adverse events included abdominal cramping, nausea, fever, soft stools, flatulence, and taste disturbance.

AUTHORS' CONCLUSIONS

Based on this systematic review and meta-analysis of 31 randomized controlled trials including 8672 patients, moderate certainty evidence suggests that probiotics are effective for preventing CDAD (NNTB = 42 patients, 95% CI 32 to 58). Our post hoc subgroup analyses to explore heterogeneity indicated that probiotics are effective among trials with a CDAD baseline risk >5% (NNTB = 12; moderate certainty evidence), but not among trials with a baseline risk ≤5% (low to moderate certainty evidence). Although adverse effects were reported among 32 included trials, there were more adverse events among patients in the control groups. The short-term use of probiotics appears to be safe and effective when used along with antibiotics in patients who are not immunocompromised or severely debilitated. Despite the need for further research, hospitalized patients, particularly those at high risk of CDAD, should be informed of the potential benefits and harms of probiotics.

Association of Krouse Classification for Sinonasal Inverted Papilloma With Recurrence: A Systematic Review and Meta-analysis

Importance

The risk factors for the recurrence of sinonasal inverted papilloma are still unclear.

Objective

To investigate the potential association between the Krouse classification and the recurrence rates of sinonasal inverted papilloma.

Data Sources

The EMBASE and MEDLINE databases were searched for the period January 1, 1964, through September 30, 2016, using the following search strategy: (paranasal sinuses [Medical Subject Headings (MeSH) terms] OR sinonasal [all fields]) AND (inverted papilloma [MeSH terms] OR (inverted [all fields] AND papilloma [all fields]).

Study Selection

The inclusion criteria were (1) studies including sinonasal inverted papilloma only and no other forms of papillomas, such as oncocytic papilloma; (2) minimum follow-up of 1 year after the surgery; and (3) clear report of cases (recurrence) and controls according to the Krouse classification system or deducible from the full-text article. Literature search was performed by 2 reviewers. Of the 625 articles retrieved in the literature, 97 full-text articles were reviewed. Observational cohort studies or randomized controlled trials were included, and the following variables were extracted from full-text articles: authors of the study, publication year, follow-up data, and number of cases (recurrence) and controls (no recurrence) in each of the 4 stages of the Krouse classification system.

Data Extraction and Synthesis

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed. Odds ratios (ORs) and 95% CIs were estimated, and data of included studies were pooled using a random-effects model.

Main Outcomes and Measures

The main outcome was recurrence after surgical removal of sinonasal inverted papilloma according to each stage of the Krouse classification system.

Results

Thirteen studies comprising 1787 patients were analyzed. A significant increased risk of recurrence (51%) was highlighted for Krouse stage T3 disease when compared with stage T2 (pooled OR, 1.51; 95% CI, 1.09-2.09). No significant difference in risk of recurrence was found between Krouse stages T1 and T2 disease (pooled OR, 1.14; 95% CI, 0.63-2.04) or between stages T3 and T4 (pooled OR, 1.27; 95% CI, 0.72-2.26).

Conclusions and Relevance

Inverted papillomas classified as stage T3 according to the Krouse classification system presented a 51% higher likelihood of recurrence. Head and neck surgeons must be aware of this higher likelihood of recurrence when planning and performing surgery for sinonasal inverted papilloma.

Living systematic reviews: 3. Statistical methods for updating meta-analyses

A living systematic review (LSR) should keep the review current as new research evidence emerges. Any meta-analyses included in the review will also need updating as new material is identified. If the aim of the review is solely to present the best current evidence standard meta-analysis may be sufficient, provided reviewers are aware that results may change at later updates. If the review is used in a decision-making context, more caution may be needed. When using standard meta-analysis methods, the chance of incorrectly concluding that any updated meta-analysis is statistically significant when there is no effect (the type I error) increases rapidly as more updates are performed. Inaccurate estimation of any heterogeneity across studies may also lead to inappropriate conclusions. This paper considers four methods to avoid some of these statistical problems when updating meta-analyses: two methods, that is, law of the iterated logarithm and the Shuster method control primarily for inflation of type I error and two other methods, that is, trial sequential analysis and sequential meta-analysis control for type I and II errors (failing to detect a genuine effect) and take account of heterogeneity. This paper compares the methods and considers how they could be applied to LSRs.

Timely Use of Probiotics in Hospitalized Adults Prevents Clostridium difficile Infection: A Systematic Review With Meta-Regression Analysis

BACKGROUND & AIMS

Systematic reviews have provided evidence for the efficacy of probiotics in preventing Clostridium difficile infection (CDI), but guidelines do not recommend probiotic use for prevention of CDI. We performed an updated systematic review to help guide clinical practice.

METHODS

We searched MEDLINE, EMBASE, International Journal of Probiotics and Prebiotics, and The Cochrane Library databases for randomized controlled trials evaluating use of probiotics and CDI in hospitalized adults taking antibiotics. Two reviewers independently extracted data and assessed risk of bias and overall quality of the evidence. Primary and secondary outcomes were incidence of CDI and adverse events, respectively. Secondary analyses examined the effects of probiotic species, dose, timing, formulation, duration, and study quality.

RESULTS

We analyzed data from 19 published studies, comprising 6261 subjects. The incidence of CDI in the probiotic cohort, 1.6% (54 of 3277), was lower than of controls, 3.9% (115 of 2984) (P < .001). The pooled relative risk of CDI in probiotic users was 0.42 (95% confidence interval, 0.30-0.57; I² = 0.0%). Meta-regression analysis demonstrated that probiotics were significantly more effective if given closer to the first antibiotic dose, with a decrement in efficacy for every day of delay in starting probiotics (P = .04); probiotics given within 2 days of antibiotic initiation produced a greater reduction of risk for CDI (relative risk, 0.32; 95% confidence interval, 0.22-0.48; I² = 0%) than later administration (relative risk, 0.70; 95% confidence interval, 0.40-1.23; I² = 0%) (P = .02). There was no increased risk for adverse events among patients given probiotics. The overall quality of the evidence was high.

CONCLUSIONS

In a systematic review with meta-regression analysis, we found evidence that administration of probiotics closer to the first dose of antibiotic reduces the risk of CDI by >50% in hospitalized adults. Future research should focus on optimal probiotic dose, species, and formulation. Systematic Review Registration: PROSPERO CRD42015016395.

Methodological systematic review identifies major limitations in prioritization processes for updating

OBJECTIVES

The aim of the study was to identify and describe strategies to prioritize the updating of systematic reviews (SRs), health technology assessments (HTAs), or clinical guidelines (CGs).

STUDY DESIGN AND SETTING

We conducted an SR of studies describing one or more methods to prioritize SRs, HTAs, or CGs for updating. We searched MEDLINE (PubMed, from 1966 to August 2016) and The Cochrane Methodology Register (The Cochrane Library, Issue 8 2016). We hand searched abstract books, reviewed reference lists, and contacted experts. Two reviewers independently screened the references and extracted data.

RESULTS

We included 14 studies. Six studies were classified as descriptive (6 of 14, 42.9%) and eight as implementation studies (8 of 14, 57.1%). Six studies reported an updating strategy (6 of 14, 42.9%), six a prioritization process (6 of 14, 42.9%), and two a prioritization criterion (2 of 14, 14.2%). Eight studies focused on SRs (8 of 14, 57.1%), six studies focused on CGs (6 of 14, 42.9%), and none were about HTAs. We identified 76 prioritization criteria that can be applied when prioritizing documents for updating. The most frequently cited criteria were as follows: available evidence (19 of 76, 25.0%), clinical relevance (10 of 76; 13.2%), and users' interest (10 of 76; 13.2%).

CONCLUSION

There is wide variability and suboptimal reporting of the methods used to develop and implement processes to prioritize updating of SRs, HTAs, and CGs.

A systematic review and meta-analysis of cross-reactivity of antibodies induced by oil-in-water emulsion adjuvanted influenza H5N1 virus monovalent vaccines

BACKGROUND

Cross-clade immunogenic stockpiled H5N1 vaccines may decrease the morbidity and transmission of infection during the initial phase of influenza pandemic. Meta-analysis of cross-reactive antibodies induced by oil-in-water emulsion adjuvanted (OWEA) influenza H5N1 virus monovalent vaccines with circulating heterologous H5N1 virus strains, isolated from human infections was performed.

METHODS

Literature search of MEDLINE, EMBASE, Web of Knowledge, The Cochrane Library, ClinicalTrials.gov, and International Standard Randomised Controlled Trial Number registry was conducted up through December 1, 2015. Methodologically qualified studies were included for (1) use of two doses of licensed OWEA (AS03 or MF59) egg-derived, inactivated influenza H5N1 virus monovalent vaccine, (2) participant age between 18 and 64years, and (3) evaluation of immunogenicity outcome for one or more subclade. Meta-analysis assessed the cross-reactivity of antibodies elicited by clade 1 adjuvanted vaccine strain against clade 2.1 virus strain (A/Vietnam/1194/2004 vs. A/Indonesia/05/2005); and separately against clade 2.2 virus strain (A/Vietnam/1194/2004 vs. A/turkey/Turkey/1/05); and clade 2.1 adjuvanted vaccine strain against clade 1 virus strain (A/Indonesia/05/2005 vs. A/Vietnam/1194/2004). Quantitative publication bias and influence analysis was conducted to evaluate potential impact of unpublished or new studies on the robustness of meta-analysis.

RESULTS

Of 960 articles, 53 qualified for quality assessment and 15 studies met the inclusion criteria. All assessed clade pairs elicited cross-reactive antibodies (clade 1 against clade 2.1 and 2.2; clade 2.1 against clade 1, 2.2, and 2.3). Heterologous strains of same sub-clade are likely to elicit higher cross-reactive antibodies.

CONCLUSIONS

OWEA influenza H5N1 virus monovalent vaccines exhibit broad cross-clade immunogenicity, a desired feature for vaccine stockpiling not yet demonstrated by unadjuvanted vaccines. In case of an impending H5N1 virus pandemic, stockpiled OWEA influenza H5N1 virus monovalent vaccines may allow population priming that could slow down the course of pandemic and could offer additional time needed for development of an effective strain specific vaccine supply.

Antipyretic Therapy in Critically Ill Septic Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

This meta-analysis aimed to examine the impact of antipyretic therapy on mortality in critically ill septic adults.

DATA SOURCES

Literature searches were implemented in Ovid Medline, Embase, Scopus, Cumulative Index of Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, and ClinicalTrials.gov through February 2016.

STUDY SELECTION

Inclusion criteria were observational or randomized studies of septic patients, evaluation of antipyretic treatment, mortality reported, and English-language version available. Studies were excluded if they enrolled pediatric patients, patients with neurologic injury, or healthy volunteers. Criteria were applied by two independent reviewers.

DATA EXTRACTION

Two reviewers independently extracted data and evaluated methodologic quality. Outcomes included mortality, frequency of shock reversal, acquisition of nosocomial infections, and changes in body temperature, heart rate, and minute ventilation. Randomized and observational studies were analyzed separately.

DATA SYNTHESIS

Eight randomized studies (1,507 patients) and eight observational studies (17,432 patients) were analyzed. Antipyretic therapy did not reduce 28-day/hospital mortality in the randomized studies (relative risk, 0.93; 95% CI, 0.77-1.13; I = 0.0%) or observational studies (odds ratio, 0.90; 95% CI, 0.54-1.51; I = 76.1%). Shock reversal (relative risk, 1.13; 95% CI, 0.68-1.90; I = 51.6%) and acquisition of nosocomial infections (relative risk, 1.13; 95% CI, 0.61-2.09; I = 61.0%) were also unchanged. Antipyretic therapy decreased body temperature (mean difference, -0.38°C; 95% CI, -0.63 to -0.13; I = 84.0%), but not heart rate or minute ventilation.

CONCLUSIONS

Antipyretic treatment does not significantly improve 28-day/hospital mortality in adult patients with sepsis.

Association between COX-2 -1195G>A polymorphism and gastrointestinal cancer risk: A meta-analysis

AIM

To perform a meta-analysis to investigate the association between cyclooxygenase-2 (COX-2) -1195G>A gene polymorphism and gastrointestinal cancers.

METHODS

Publications related to the COX-2 -1195G>A gene polymorphism and gastrointestinal cancers published before July 2016 were retrieved from PubMed, EMBASE, Web of Science, China Biological Medicine Database, China National Knowledge Infrastructure, and CQVIP Database. Meta-analysis was performed using Stata11.0 software. The strength of the association was evaluated by calculating the combined odds ratios (ORs) and the corresponding 95%CIs. The retrieved publications were excluded or included one by one for sensitivity analysis. In addition, the funnel plot, Begg’s rank correlation test, and Egger’s linear regression method were applied to analyse whether the included publications had publication bias.

RESULTS

A total of 24 publications related to the COX-2 -1195G>A gene polymorphism were included, including 28 studies involving 11043 cases and 18008 controls. The meta-analysis results showed that the COX-2 -1195G>A gene polymorphism significantly correlated with an increased risk of gastrointestinal cancers, particularly gastric cancer (A vs G: OR = 1.35; AA/AG vs GG: OR = 1.54; AA vs GG/AG: OR = 1.43; AA vs GG: OR = 1.80; AG vs GG: OR = 1.35). Compared to the Caucasian population in America and Europe, the COX-2 -1195G>A gene polymorphism in the Asian population (A vs G: OR = 1.30; AA/AG vs GG: OR = 1.50; AA vs GG/AG: OR = 1.35; AA vs GG: OR = 1.71; AG vs GG: OR = 1.37) significantly increased gastrointestinal cancer risk. The sensitivity analysis (P < 0.05) and the false positive report probability (P < 0.2) confirmed the reliability of the results.

CONCLUSION

The results showed that the COX-2 -1195G>A gene polymorphism might be a potential risk factor for gastrointestinal cancers. Further validation by a large homogeneous study is warranted.

Associations between AT-rich interactive domain 5B gene polymorphisms and risk of childhood acute lymphoblastic leukemia: a meta-analysis

Previous genome-wide association studies (GWAS) have implicated several single nucleotide polymorphisms (SNPs) in the AT-rich interactive domain 5B (ARID5B) gene with childhood acute lymphoblastic leukemia (ALL). However, replicated studies reported some inconsistent results in different populations. Using meta-analysis, we here aimed to clarify the nature of the genetic risks contributed by the two polymorphisms (rs10994982, rs7089424) for developing childhood ALL. Through searches of PubMed, EMBASE, and manually searching relevant references, a total of 14 articles with 16 independent studies were included. Odds ratios (ORs) with 95% confidence intervals (95%CI) were calculated to assess the associations. Both SNPs rs10994982 and rs7089424 showed significant associations with childhood ALL risk in all genetic models after Bonferroni correction. Furthermore, subtype analyses of B-lineage ALL provided strong evidence that SNP rs10994982 is highly associated with the risk of developing B-hyperdiploid ALL. These results indicate that SNPs rs10994982 and rs7089424 are indeed significantly associated with increased risk of childhood ALL.

Prioritizing covariates in the planning of future studies in the meta-analytic framework

Science can be seen as a sequential process where each new study augments evidence to the existing knowledge. To have the best prospects to make an impact in this process, a new study should be designed optimally taking into account the previous studies and other prior information. We propose a formal approach for the covariate prioritization, that is the decision about the covariates to be measured in a new study. The decision criteria can be based on conditional power, change of the p-value, change in lower confidence limit, Kullback-Leibler divergence, Bayes factors, Bayesian false discovery rate or difference between prior and posterior expectation. The criteria can be also used for decisions on the sample size. As an illustration, we consider covariate prioritization based on genome-wide association studies for C-reactive protein levels and make suggestions on the genes to be studied further.

Observational Studies of Drug Safety in Multi-Database Studies: Methodological Challenges and Opportunities

INTRODUCTION/OBJECTIVE

The Canadian Network for Observational Drug Effect Studies (CNODES), a network of researchers and databases, is a collaborating center of the Drug Safety and Effectiveness Network. CNODES' main mandate is to conduct observational studies of drug safety based on queries developed and submitted by Health Canada and other federal, provincial, and territorial stakeholders. Through a case study we explore several methodological opportunities and challenges that arise in distributed pharmacoepidemiology networks.

CASE STUDY

We use as a case study a study of proton pump inhibitors and hospitalization for community-acquired pneumonia. Challenges arise in the design and conduct of studies at individual sites, and then with processes and methods for combining data. On the other hand, distributed networks provide opportunities, such as the ability to detect and understand heterogeneity, in sample sizes that would typically be impossible for a single study.

CONCLUSIONS

Networks such as CNODES provide the opportunity to detect and quantify important safety signals from administrative data, and provide many challenges for methods research in pharmacoepidemiology using distributed data. As networks increase in size and scope of research questions, the need for methodological developments should continue to grow.

Planning future studies based on the precision of network meta-analysis results

When there are multiple competing interventions for a healthcare problem, the design of new studies could be based on the entire network of evidence as reflected in a network meta-analysis. There is a practical need to answer how many (if any) studies are needed, of which design (i.e., which treatments to compare), and with what sample size to infer conclusively about the relative treatment effects of a set of target or all competing treatments and their relative ranking. We consider the precision in the results obtained from network meta-analysis: the precision of the joint distribution of the estimated basic parameters of the model and the precision in the treatment ranking. We quantify the precision in the estimated effects by considering their variance-covariance matrix and estimate the precision in ranking by quantifying the dissimilarity of the density functions of summary effect estimates. Then, based on a desirable improvement in precision, we calculate the required sample size for each possible study design and number of study arms, and we present visual tools that can help trialists select the optimal study design. We use a published network of interventions for the treatment of hepatocellular carcinoma to illustrate the suggested methodology. The presented methodology can aid investigators making informed and evidence-based decisions about planning new studies.

How would increasing seat belt use affect the number of killed or seriously injured light vehicle occupants?

The expected effects of increasing seat belt use on the number of killed or seriously injured (KSI) light vehicle occupants have been estimated for three scenarios of increased seat belt use in Norway, taking into account current seat belt use, the effects of seat belts and differences in crash risk between belted and unbelted drivers. The effects of seat belts on fatality and injury risk were investigated in a meta-analysis that is based on 24 studies from 2000 or later. The results indicate that seat belts reduce both fatal and non-fatal injuries by 60% among front seat occupants and by 44% among rear seat occupants. Both results are statistically significant. Seat belt use among rear seat occupants was additionally found to about halve fatality risk among belted front seat occupants in a meta-analysis that is based on six studies. Based on an analysis of seat belt wearing rates among crash involved and non-crash involved drivers in Norway it is estimated that unbelted drivers have 8.3 times the fatal crash risk and 5.2 times the serious injury crash risk of belted drivers. The large differences in crash risk are likely to be due to other risk factors that are common among unbelted drivers such as drunk driving and speeding. Without taking into account differences in crash risk between belted and unbelted drivers, the estimated effects of increasing seat belt use are likely to be biased. When differences in crash risk are taken into account, it is estimated that the annual numbers of KSI front seat occupants in light vehicles in Norway could be reduced by 11.3% if all vehicles had seat belt reminders (assumed seat belt wearing rate 98.9%), by 17.5% if all light vehicles had seat belt interlocks (assumed seat belt wearing rate 99.7%) and by 19.9% if all front seat occupants of light vehicles were belted. Currently 96.6% of all (non-crash involved) front seat occupants are belted. The effect on KSI per percentage increase of seat belt use increases with increasing initial levels of seat belt use. Had all rear seat occupants been belted, the number of KSI front seat occupants could additionally be reduced by about 0.6%. The reduction of the number of KSI rear seat occupants would be about the same in terms of numbers of prevented KSI.

Endoscopic and Open Release Similarly Safe for the Treatment of Carpal Tunnel Syndrome. A Systematic Review and Meta-Analysis

BACKGROUND

The Endoscopic Release of Carpal Tunnel Syndrome (ECTR) is a minimal invasive approach for the treatment of Carpal Tunnel Syndrome. There is scepticism regarding the safety of this technique, based on the assumption that this is a rather "blind" procedure and on the high number of severe complications that have been reported in the literature.

PURPOSE

To evaluate whether there is evidence supporting a higher risk after ECTR in comparison to the conventional open release.

METHODS

We searched MEDLINE (January 1966 to November 2013), EMBASE (January 1980 to November 2013), the Cochrane Neuromuscular Disease Group Specialized Register (November 2013) and CENTRAL (2013, issue 11 in The Cochrane Library). We hand-searched reference lists of included studies. We included all randomized or quasi-randomized controlled trials (e.g. study using alternation, date of birth, or case record number) that compare any ECTR with any OCTR technique. Safety was assessed by the incidence of major, minor and total number of complications, recurrences, and re-operations.The total time needed before return to work or to return to daily activities was also assessed. We synthesized data using a random-effects meta-analysis in STATA. We conducted a sensitivity analysis for rare events using binomial likelihood. We judged the conclusiveness of meta-analysis calculating the conditional power of meta-analysis.

CONCLUSIONS

ECTR is associated with less time off work or with daily activities. The assessment of major complications, reoperations and recurrence of symptoms does not favor either of the interventions. There is an uncertain advantage of ECTR with respect to total minor complications (more transient paresthesia but fewer skin-related complications). Future studies are unlikely to alter these findings because of the rarity of the outcome. The effect of a learning curve might be responsible for reduced recurrences and reoperations with ECTR in studies that are more recent, although formal statistical analysis failed to provide evidence for such an association.

LEVEL OF EVIDENCE

I.

Endoscopic and Open Release Similarly Safe for the Treatment of Carpal Tunnel Syndrome. A Systematic Review and Meta-Analysis

Background

The Endoscopic Release of Carpal Tunnel Syndrome (ECTR) is a minimal invasive approach for the treatment of Carpal Tunnel Syndrome. There is scepticism regarding the safety of this technique, based on the assumption that this is a rather “blind” procedure and on the high number of severe complications that have been reported in the literature.

Purpose

To evaluate whether there is evidence supporting a higher risk after ECTR in comparison to the conventional open release.

Methods

We searched MEDLINE (January 1966 to November 2013), EMBASE (January 1980 to November 2013), the Cochrane Neuromuscular Disease Group Specialized Register (November 2013) and CENTRAL (2013, issue 11 in The Cochrane Library). We hand-searched reference lists of included studies. We included all randomized or quasi-randomized controlled trials (e.g. study using alternation, date of birth, or case record number) that compare any ECTR with any OCTR technique. Safety was assessed by the incidence of major, minor and total number of complications, recurrences, and re-operations.The total time needed before return to work or to return to daily activities was also assessed. We synthesized data using a random-effects meta-analysis in STATA. We conducted a sensitivity analysis for rare events using binomial likelihood. We judged the conclusiveness of meta-analysis calculating the conditional power of meta-analysis.

Conclusions

ECTR is associated with less time off work or with daily activities. The assessment of major complications, reoperations and recurrence of symptoms does not favor either of the interventions. There is an uncertain advantage of ECTR with respect to total minor complications (more transient paresthesia but fewer skin-related complications). Future studies are unlikely to alter these findings because of the rarity of the outcome. The effect of a learning curve might be responsible for reduced recurrences and reoperations with ECTR in studies that are more recent, although formal statistical analysis failed to provide evidence for such an association. Level of evidence: I.

Laser treatment of drusen to prevent progression to advanced age-related macular degeneration

BACKGROUND

Drusen are amorphous yellowish deposits beneath the sensory retina. People with drusen, particularly large drusen, are at higher risk of developing age-related macular degeneration (AMD). The most common complication in AMD is choroidal neovascularisation (CNV), the growth of new blood vessels in the centre of the macula. The risk of CNV is higher among people who are already affected by CNV in one eye.It has been observed clinically that laser photocoagulation of drusen leads to their disappearance and may prevent the occurrence of advanced disease (CNV or geographic atrophy) associated with visual loss.

OBJECTIVES

To examine the effectiveness and adverse effects of laser photocoagulation of drusen in AMD.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2015), EMBASE (January 1980 to August 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to August 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 3 August 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of laser treatment of drusen in AMD in which laser treatment had been compared with no intervention or sham treatment. Two types of trials were included. Some trials studied one eye of each participant (unilateral studies); other studies recruited participants with bilateral drusen and randomised one eye to photocoagulation or control and the fellow eye to the other group.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We pooled data from unilateral and bilateral studies using a random-effects model. For the bilateral studies, we estimated the within-person correlation coefficient from one study and assumed it was valid for the others.

MAIN RESULTS

The update of this review found two additional studies, totaling 11 studies that randomised 2159 participants (3580 eyes) and followed them up to two years, of which six studies (1454 participants) included people with one eye randomised to treatment and one to control. Studies were conducted in Australia, Europe and North America.Overall, the risk of bias in the included studies was low, particularly for the larger studies and for the primary outcome development of CNV. Photocoagulation did not reduce the development of CNV at two years' follow-up (odds ratio (OR) 1.07, 95% confidence interval (CI) 0.79 to 1.46, 11 studies, 2159 participants (3580 eyes), high quality evidence). This estimate means that, given an overall occurrence of CNV of 8.3% in the control group, we estimated an absolute risk reduction by no more than 1.4% in the laser group, according to the lower CI limit. Only two studies investigated the effect on the development of geographic atrophy and could not show a difference, but estimates were imprecise (OR 1.30, 95% CI 0.38 to 4.51, two studies, 148 participants (148 eyes), low quality evidence).Among secondary outcomes, photocoagulation led to drusen reduction (OR 9.16, 95% CI 6.28 to 13.4, three studies, 570 participants (944 eyes), high quality evidence) but was not shown to limit loss of 3 or more lines of visual acuity (OR 0.99, 95% CI 0.81 to 1.22, nine studies, 2002 participants (2386 eyes), moderate quality evidence).In a subgroup analysis, no difference could be shown for conventional visible (eight studies) versus subthreshold invisible (four studies) photocoagulation for the primary outcomes (P value = 0.29). The effect in the subthreshold group did not suggest a relevant benefit (OR 1.27, 95% CI 0.82 to 1.98). No study used micropulse subthreshold photocoagulation.No other adverse effects (apart from development of CNV, geographic atrophy or visual loss) were reported.

AUTHORS' CONCLUSIONS

The trials included in this review confirm the clinical observation that laser photocoagulation of drusen leads to their disappearance. However, treatment does not result in a reduction in the risk of developing CNV, and was not shown to limit the occurrence of geographic atrophy or visual acuity loss.Ongoing studies are being conducted to assess whether the use of extremely short laser pulses (i.e. nanosecond laser treatment) cannot only lead to drusen regression but also prevent neovascular AMD.