Assessing treatment effect heterogeneity in the presence of missing effect modifier data in cluster-randomized trials

Understanding whether and how treatment effects vary across subgroups is crucial to inform clinical practice and recommendations. Accordingly, the assessment of heterogeneous treatment effects based on pre-specified potential effect modifiers has become a common goal in modern randomized trials. However, when one or more potential effect modifiers are missing, complete-case analysis may lead to bias and under-coverage. While statistical methods for handling missing data have been proposed and compared for individually randomized trials with missing effect modifier data, few guidelines exist for the cluster-randomized setting, where intracluster correlations in the effect modifiers, outcomes, or even missingness mechanisms may introduce further threats to accurate assessment of heterogeneous treatment effect. In this article, the performance of several missing data methods are compared through a simulation study of cluster-randomized trials with continuous outcome and missing binary effect modifier data, and further illustrated using real data from the Work, Family, and Health Study. Our results suggest that multilevel multiple imputation and Bayesian multilevel multiple imputation have better performance than other available methods, and that Bayesian multilevel multiple imputation has lower bias and closer to nominal coverage than standard multilevel multiple imputation when there are model specification or compatibility issues.

Sample size estimation for stratified cluster randomization trial with survival endpoint

Cluster randomization trials with survival endpoint are predominantly used in drug development and clinical care research when drug treatments or interventions are delivered at a group level. Unlike conventional cluster randomization design, stratified cluster randomization design is generally considered more effective in reducing the impacts of imbalanced baseline prognostic factors and varying cluster sizes between groups when these stratification factors are adopted in the design. Failure to account for stratification and cluster size variability may lead to underpowered analysis and inaccurate sample size estimation. Apart from the sample size estimation in unstratified cluster randomization trials, there are no development of an explicit sample size formula for survival endpoint when a stratified cluster randomization design is employed. In this article, we present a closed-form sample size formula based on the stratified cluster log-rank statistics for stratified cluster randomization trials with survival endpoint. It provides an integrated solution for sample size estimation that account for cluster size variation, baseline hazard heterogeneity, and the estimated intracluster correlation coefficient based on the preliminary data. Simulation studies show that the proposed formula provides the appropriate sample size for achieving the desired statistical power under various parameter configurations. A real example of a stratified cluster randomization trial in the population with stable coronary heart disease is presented to illustrate our method.

Optimal allocation strategies in platform trials with continuous endpoints

Platform trials are randomized clinical trials that allow simultaneous comparison of multiple interventions, usually against a common control. Arms to test experimental interventions may enter and leave the platform over time. This implies that the number of experimental intervention arms in the trial may change as the trial progresses. Determining optimal allocation rates to allocate patients to the treatment and control arms in platform trials is challenging because the optimal allocation depends on the number of arms in the platform and the latter typically varies over time. In addition, the optimal allocation depends on the analysis strategy used and the optimality criteria considered. In this article, we derive optimal treatment allocation rates for platform trials with shared controls, assuming that a stratified estimation and a testing procedure based on a regression model are used to adjust for time trends. We consider both, analysis using concurrent controls only as well as analysis methods using concurrent and non-concurrent controls and assume that the total sample size is fixed. The objective function to be minimized is the maximum of the variances of the effect estimators. We show that the optimal solution depends on the entry time of the arms in the trial and, in general, does not correspond to the square root of k allocation rule used in classical multi-arm trials. We illustrate the optimal allocation and evaluate the power and type 1 error rate compared to trials using one-to-one and square root of k allocations by means of a case study.

Problematic meta-analyses: Bayesian and frequentist perspectives on combining randomized controlled trials and non-randomized studies

PURPOSE

In the literature, the propriety of the meta-analytic treatment-effect produced by combining randomized controlled trials (RCT) and non-randomized studies (NRS) is questioned, given the inherent confounding in NRS that may bias the meta-analysis. The current study compared an implicitly principled pooled Bayesian meta-analytic treatment-effect with that of frequentist pooling of RCT and NRS to determine how well each approach handled the NRS bias.

MATERIALS & METHODS

Binary outcome Critical-Care meta-analyses, reflecting the importance of such outcomes in Critical-Care practice, combining RCT and NRS were identified electronically. Bayesian pooled treatment-effect and 95% credible-intervals (BCrI), posterior model probabilities indicating model plausibility and Bayes-factors (BF) were estimated using an informative heavy-tailed heterogeneity prior (half-Cauchy). Preference for pooling of RCT and NRS was indicated for Bayes-factors > 3 or < 0.333 for the converse. All pooled frequentist treatment-effects and 95% confidence intervals (FCI) were re-estimated using the popular DerSimonian-Laird (DSL) random effects model.

RESULTS

Fifty meta-analyses were identified (2009-2021), reporting pooled estimates in 44; 29 were pharmaceutical-therapeutic and 21 were non-pharmaceutical therapeutic. Re-computed pooled DSL FCI excluded the null (OR or RR = 1) in 86% (43/50). In 18 meta-analyses there was an agreement between FCI and BCrI in excluding the null. In 23 meta-analyses where FCI excluded the null, BCrI embraced the null. BF supported a pooled model in 27 meta-analyses and separate models in 4. The highest density of the posterior model probabilities for 0.333 < Bayes factor < 1 was 0.8.

CONCLUSIONS

In the current meta-analytic cohort, an integrated and multifaceted Bayesian approach gave support to including NRS in a pooled-estimate model. Conversely, caution should attend the reporting of naïve frequentist pooled, RCT and NRS, meta-analytic treatment effects.

Representation of Racial and Ethnic Minorities in Nephrology Clinical Trials: A Systematic Review and Meta-Analysis

SIGNIFICANCE STATEMENT

Racial and ethnic disparities in clinical trial enrollment are well described. However, whether these disparities are present in nephrology randomized clinical trials has not been previously reported. We performed a systematic review and meta-analysis of 380 randomized clinical trials involving different aspects of kidney disease published between 2000 and 2021. Our results indicate that worldwide reporting of race and ethnicity is poor and that White individuals account for most of the randomized participants with decreased enrollment of Black participants in more recent trials. However, trials conducted in the United States have representation of Black and Hispanic participants consistent with the population prevalence of disease and under-representation of Asian participants.

BACKGROUND

Under-representation of racial and ethnic minorities in clinical trials could worsen disparities, but reporting and enrollment practices in nephrology randomized clinical trials have not been described.

METHODS

PubMed was searched to capture randomized clinical trials for five kidney disease-related conditions published between 2000 and 2021 in ten high-impact journals. We excluded trials with <50 participants and pilot trials. Outcomes of interest were the proportion of trials reporting race and ethnicity and the proportions of enrolled participants in each race and ethnicity category.

RESULTS

Among 380 trials worldwide, race was reported in just over half and ethnicity in 12%. Most enrolled participants were White, and Black individuals accounted for ≤10% of participants except in dialysis trials where they accounted for 26% of participants. However, Black participants were enrolled at high proportions relative to disease and population prevalence in US CKD, dialysis, and transplant trials representing 19% of participants in AKI, 26% in CKD, 44% in GN, 40% in dialysis, and 26% in transplant trials. Enrollment of Asian participants was low worldwide except in GN trials with marked under-representation in US CKD, dialysis, and transplant trials. Hispanic individuals represented only 13% of participants in US dialysis trials compared with 29% of US dialysis population.

CONCLUSION

More complete reporting of race and ethnicity in nephrology trials is needed. Black and Hispanic patients are well-represented in kidney disease trials in the United States. Asian patients are poorly represented in kidney trials both globally and in the United States.

Assessing intervention effects in a randomized trial within a social network

Studies of social networks provide unique opportunities to assess the causal effects of interventions that may impact more of the population than just those intervened on directly. Such effects are sometimes called peer or spillover effects, and may exist in the presence of interference, that is, when one individual's treatment affects another individual's outcome. Randomization-based inference (RI) methods provide a theoretical basis for causal inference in randomized studies, even in the presence of interference. In this article, we consider RI of the intervention effect in the eX-FLU trial, a randomized study designed to assess the effect of a social distancing intervention on influenza-like-illness transmission in a connected network of college students. The approach considered enables inference about the effect of the social distancing intervention on the per-contact probability of influenza-like-illness transmission in the observed network. The methods allow for interference between connected individuals and for heterogeneous treatment effects. The proposed methods are evaluated empirically via simulation studies, and then applied to data from the eX-FLU trial.

Determining reference ranges and sample sizes in parallel-group studies

BACKGROUND AND OBJECTIVES

Reference ranges are widely used to locate the major range of the target probability distribution. When future measurements fall outside the reference range, they are classified as atypical and require further investigation. The fundamental principles and statistical properties of reference ranges are closely related to those of tolerance interval procedures. Existing investigations of reference ranges and tolerance intervals mainly devoted to the primitive cases of one- and paired-sample designs. Although reference ranges hold considerable promise for parallel group designs, the corresponding methodological and computational issues for determining reference limits and sample sizes have not been adequately addressed.

METHODS

This paper describes a complete collection of one- and two-sided reference ranges for assessing measurement differences in parallel-group studies that assume variance homogeneity.

RESULTS

The problem of sample size determination for precise reference ranges is also examined under the expected half-width and assurance probability considerations. Unlike the current methods, the suggested sample size criteria explicitly accommodate desired interval width in precise interval estimation.

CONCLUSIONS

Theoretical examinations and empirical assessments are presented to validate the usefulness of the proposed reference range and sample size procedures. To enhance the usages of the recommended techniques in practical applications, computer programs are developed for efficient calculation and exact analysis. A real data example regarding tablet absorption rate and extent is presented to illustrate the suggested assessments between two drug formulations.

Saphenous vein harvesting techniques for coronary artery bypass grafting: a systematic review and meta-analysis

The great saphenous vein (GSV) graft remains a frequently used conduit for coronary artery bypass graft (CABG) surgery. The optimal technique for GSV harvesting has been the subject of on-going controversy. We therefore sought to conduct a systematic review and meta-analysis of all available GSV harvesting techniques in CABG. A systematic search of 12 electronic databases was performed to identify all randomized controlled trials (RCTs) of any GSV harvesting technique, including conventional vein harvesting (CVH), no-touch, standard bridging technique (SBT) and endoscopic vein harvesting (EVH) techniques. We investigated safety and long-term efficacy outcomes. All outcomes were analyzed using the frequentist network meta-analysis. A total of 6480 patients from 34 RCTs were included. For safety outcomes, EVH reduced 91% and 77% risk of wound infection compared to no-touch and CVH, respectively. EVH and SBT also significantly reduced the risk of sensibility disorder and postoperative pain. The techniques were not significantly different regarding long-term efficacy outcomes, including mortality, myocardial infarction and graft patency. For GSV harvesting for CABG, EVH techniques are the most favorable, but in case of using an open technique, no-touch is more recommended than CVH. More effective and safer procedures should be investigated for GSV harvesting in CABG.

Randomized controlled trial to test the efficacy of a brief, communication-based, substance use preventive intervention for parents of adolescents: Protocol for the SUPPER Project (Substance Use Prevention Promoted by Eating family meals Regularly)

Background

Substance use among adolescents in the U.S. is associated with adverse physical and mental health outcomes in the long-term. Universal youth-focused substance use prevention programs have demonstrated effectiveness but are often not sustainable due to the significant amount of time, effort, and resources required. We describe a trial protocol for a brief, low-participant-burden intervention to improve substance use-specific parent-child communication through the promotion of family meals and increased parental engagement.

Methods

This study is a parallel-group randomized controlled trial designed to assess the efficacy of a 13-week intervention. A total of 500 dyads of parents and their 5^th-7^th grade children are recruited from across Massachusetts. Dyads are randomized to the intervention or attention-control condition using block urn randomization, based on child grade, gender, and school. Parents/guardians in the substance use preventive intervention arm receive a short handbook, attend two meetings with an interventionist, and receive two SMS messages per week. Parents/guardians in the control arm receive the same dose but with content focused on nutrition, physical activity, and weight stigma. Participant dyads submit videos of family meals, audio recordings of prompted conversations, and quantitative surveys over an 18-month period (baseline, 3, 6, 12, 18 months post-intervention). The primary outcomes measure the quantity and quality of parent-child substance use conversations and proximal child indicators (i.e., substance use attitudes and expectancies, affiliation with substance-using peers, and intentions and willingness to use substances). The secondary outcome is child substance use initiation.

Discussion

This is a novel, brief, communication-focused intervention for parents/guardians that was designed to reduce participant burden. The intervention has the potential to improve parent-child engagement and communication and conversations about substance use specifically and decrease child substance use risk factors and substance use initiation.

Trial registration

ClinicalTrials.gov NCT03925220. Registered on 24 April 2019.

Predictors, Moderators, and Mediators Associated With Treatment Outcome in Randomized Clinical Trials Among Adolescents With Depression: A Scoping Review

Importance

The application of precision medicine principles for the treatment of depressive disorders in adolescents requires an examination of the variables associated with depression outcomes in randomized clinical trials (RCTs).

Objective

To describe predictors, moderators, and mediators associated with outcomes in RCTs for the treatment of depressive disorders in adolescents.

Evidence Review

A scoping review of RCTs for the treatment of depression in adolescents was conducted. Databases searched included MEDLINE, Embase, APA PsycInfo, and CINAHL. Included publications tested predictors, moderators, and/or mediators associated with depression symptom outcomes (eg, symptom reduction, response, remission) in RCTs pertaining to the treatment of adolescents, ages 13 to 17 years. Predictors were defined as variables that were associated with depression outcomes, independent of treatment group. Moderators were defined as baseline variables that were associated with differential outcomes between treatment groups. Mediators were defined by a formal mediation analysis. In duplicate, variables were extracted and coded with respect to analysis type (univariable or multivariable), statistical significance, direction of effect size, reporting of a priori hypotheses, and adjustment for multiple comparisons. Aggregated results were summarized by variable domain and RCT sample.

Findings

Eighty-one articles reporting on variables associated with outcomes across 33 RCTs were identified, including studies of biological (10 RCTs), psychosocial (18 RCTs), and combined (4 RCTs) treatments as well as a service delivery model (1 RCT). Fifty-three variable domains were tested as baseline predictors of depression outcome, 41 as moderators, 19 as postbaseline predictors, and 5 as mediators. Variable domains that were reported as significant in at least 3 RCTs included age, sex/gender, baseline depression severity, early response to treatment, sleep changes, parent-child conflict, overall psychopathology, suicidal ideation, hopelessness, functional impairment, attendance at therapy sessions, and history of trauma. Two publications reported a priori hypotheses and adjustment for multiple comparisons, both finding that baseline depression severity and family conflict were associated with poorer outcomes.

Conclusions and Relevance

This review identified commonly researched variables requiring more scrutiny as well as underresearched variables to inform future study designs. Further efforts to discover predictors, moderators, and mediators associated with treatment response have great potential to optimize care for adolescents with depression.

Geographical Representation of Low- and Middle-Income Countries in Randomized Clinical Trials for COVID-19

This systematic review examines geographical representation of low- and middle-income countries in randomized clinical trials for COVID-19 compared with high-income countries.

Analysis of 567,758 randomized controlled trials published over 30 years reveals trends in phrases used to discuss results that do not reach statistical significance

The power of language to modify the reader's perception of interpreting biomedical results cannot be underestimated. Misreporting and misinterpretation are pressing problems in randomized controlled trials (RCT) output. This may be partially related to the statistical significance paradigm used in clinical trials centered around a P value below 0.05 cutoff. Strict use of this P value may lead to strategies of clinical researchers to describe their clinical results with P values approaching but not reaching the threshold to be "almost significant." The question is how phrases expressing nonsignificant results have been reported in RCTs over the past 30 years. To this end, we conducted a quantitative analysis of English full texts containing 567,758 RCTs recorded in PubMed between 1990 and 2020 (81.5% of all published RCTs in PubMed). We determined the exact presence of 505 predefined phrases denoting results that approach but do not cross the line of formal statistical significance (P < 0.05). We modeled temporal trends in phrase data with Bayesian linear regression. Evidence for temporal change was obtained through Bayes factor (BF) analysis. In a randomly sampled subset, the associated P values were manually extracted. We identified 61,741 phrases in 49,134 RCTs indicating almost significant results (8.65%; 95% confidence interval (CI): 8.58% to 8.73%). The overall prevalence of these phrases remained stable over time, with the most prevalent phrases being "marginally significant" (in 7,735 RCTs), "all but significant" (7,015), "a nonsignificant trend" (3,442), "failed to reach statistical significance" (2,578), and "a strong trend" (1,700). The strongest evidence for an increased temporal prevalence was found for "a numerical trend," "a positive trend," "an increasing trend," and "nominally significant." In contrast, the phrases "all but significant," "approaches statistical significance," "did not quite reach statistical significance," "difference was apparent," "failed to reach statistical significance," and "not quite significant" decreased over time. In a random sampled subset of 29,000 phrases, the manually identified and corresponding 11,926 P values, 68,1% ranged between 0.05 and 0.15 (CI: 67. to 69.0; median 0.06). Our results show that RCT reports regularly contain specific phrases describing marginally nonsignificant results to report P values close to but above the dominant 0.05 cutoff. The fact that the prevalence of the phrases remained stable over time indicates that this practice of broadly interpreting P values close to a predefined threshold remains prevalent. To enhance responsible and transparent interpretation of RCT results, researchers, clinicians, reviewers, and editors may reduce the focus on formal statistical significance thresholds and stimulate reporting of P values with corresponding effect sizes and CIs and focus on the clinical relevance of the statistical difference found in RCTs.

Assessing the efficacy of an integrated intervention to create demand for fishermen’s schistosomiasis and HIV services (FISH) in Mangochi, Malawi: Study protocol for a cluster randomized control trial

Background

Both HIV and schistosomiasis are major public health problems worldwide with 1.8 million new HIV infections, and up to 110 million untreated schistosomiasis cases globally. Although a causal link has not been established, there are strong suggestions that having schistosomiasis increases onward transmission of HIV from co-infected men to women. With both HIV and schistosomiasis treatment readily available in Malawi, there is a need to investigate the feasibility, acceptability and health impacts of joint management of these two hazards, with special focus on health education and demand-creation for fishermen. The aim of this project is to identify optimal models of delivering integrated HIV and schistosomiasis services for fishermen, particularly investigating the effect of using social networks, HIV self-test kits and beach clinic services in Mangochi, Malawi.

Methods

We have mapped 45 boat teams or landing sites for a 3-arm cluster randomized trial using “boat team” as the unit of randomization. The three arms are: 1) Standard of care (SOC) with leaflets explaining the importance of receiving presumptive treatment for schistosomiasis (praziquantel) and HIV services for fishermen, and two intervention arms of 2) SOC + a peer explaining the leaflet to his fellow fishermen in a boat team; and 3) arm 2 with HIV self-test kits delivered to the boat team fishermen by the peer. The primary outcomes measured at 9 months of trial delivery will compare differences between arms in the proportions of boat-team fishermen: 1) who self-report starting antiretroviral therapy or undergoing voluntary medical male circumcision; and 2) who have ≥1 S. haematobium egg seen on light microscopy of the filtrate from 10mls urine (“egg-positive”).

Discussion

This is the first evaluation of an integrated HIV and schistosomiasis services intervention for fishermen, particularly investigating the effect of using social networks, HIVST kits and beach clinic services. The findings will support future efforts to integrate HIVST with other health services for fishermen in similar settings if found to be efficacious.

Trial registration

This trial is registered in the ISRCTN registry: ISRCTN14354324; date of registration: 05 October 2020. https://www.isrctn.com/ISRCTN14354324?q=ISRCTN14354324&filters=&sort=&offset=1&totalResults=1&page=1&pageSize=10&searchType=basic-search.

Linked to protocol version number 1.4 of 11 January 2021.

Reporting of Physicians' or Investigators' Choice of Treatment in Oncology Randomized Clinical Trials

This cross-sectional study examines the prevalence of restricted choice of treatment in control groups among physicians and investigators conducting oncology randomized clinical trials (RCTs).

Association of Single-blind Placebo Run-in Periods With the Placebo Response in Randomized Clinical Trials of Antidepressants: A Systematic Review and Meta-analysis

Importance

Single-blind placebo run-in (PRI) periods are common in randomized clinical trials (RCTs) of treatment for depression. They aim to increase sensitivity to detect drug effects; however, the association of PRI periods with study outcomes remains unclear. This is concerning given the costs of PRI periods to patients and investigators.

Objective

To examine the association of the use of PRI periods with the placebo response, drug response, and drug-placebo difference among RCTs of antidepressants.

Data Sources

MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and PsycINFO, as well as repositories of unpublished studies, were systematically searched up to July 2021.

Study Selection

Included studies were double-blind, placebo-controlled RCTs of antidepressant medication among adults with depressive disorders.

Data Extraction and Synthesis

Data were extracted into a coding sheet, including the characteristics of studies, the characteristics of PRI periods, and the outcomes of studies.

Main Outcomes and Measures

Study outcomes were the primary depression symptom measure reported by the RCT. These outcomes were used to calculate effect sizes (Hedges g) of the within-group drug response and placebo response as well as the drug-placebo difference. Random-effects meta-analysis was used to calculate effect sizes, and subgroup analyses were used to compare outcomes depending on use of PRI periods.

Results

A total of 347 trials (representing 89 183 participants) were included; 174 studies (50%) reported using a single-blind PRI period. Response outcome data were available for 189 studies. Studies using PRI periods reported a smaller placebo response (g = 1.05 [95% CI, 0.98-1.11]; I2 = 82%) than studies that did not use a PRI period (g = 1.15 [95% CI, 1.09-1.21]; I2 = 81%; P = .02). Subgroup analysis showed a larger drug response size among studies that did not use a PRI period (g = 1.55 [95% CI, 1.49-1.61]; I2 = 85%) than those that did use a PRI period (g = 1.42 [95% CI, 1.36-1.48]; I2 = 81%; P = .001). The drug-placebo difference did not differ by use of PRI periods (g = 0.33 [95% CI, 0.29-0.38]; I2 = 47% for use of a PRI period vs g = 0.34 [95% CI, 0.30-0.38]; I2 = 54% for no use of PRI periods; P = .92). The likelihood of response to drug vs placebo also did not differ between studies that used a PRI period (odds ratio, 1.89 [95% CI, 1.76-2.03]) and those that did not use a PRI period (odds ratio, 1.77 [95% CI, 1.65-1.89]; P = .18).

Conclusions and Relevance

This study suggests that RCTs using PRI periods yield smaller within-group changes across both placebo and drug groups compared with RCTs without PRI periods. The reduction in effect size across groups was equivalent in magnitude. Consequently, PRI studies do not observe larger drug-placebo differences, suggesting that they do not increase trial sensitivity. As such, given the resources and probable deception required and risk to external validity, the practice of using PRI periods in RCTs of antidepressants should be ended.

Syndrome Differentiation and Treatment Regularity in Traditional Chinese Medicine for Type 2 Diabetes: A Text Mining Analysis

Objective

The goal of this study was to systematically summarize and categorize the syndrome differentiation, medication rules, and acupoint therapy in the domestic traditional Chinese medicine (TCM) literature on type 2 diabetes mellitus (T2DM), such that guidelines and new insights can be provided for future practitioners and researchers.

Methods

Taking randomized controlled trials (RCTs) on the treatment of T2DM in TCM as the research theme, we searched for full-text literature in three major clinical databases, including CNKI, Wan Fang, and VIP, published between 1990 and 2020. We then conducted frequency statistics, cluster analysis, association rules extraction, and topic modeling based on a corpus of medical academic words extracted from 3,654 research articles.

Results

The TCM syndrome types, subjective symptoms, objective indicators, Chinese herbal medicine, acupuncture points, and TCM prescriptions for T2DM were compiled based on invigorating the kidney and Qi, nourishing Yin, and strengthening the spleen. Most TCM syndrome differentiation for T2DM was identified as "Zhongxiao" (the lesion in the spleen and stomach) and "Xiaxiao" (the lesion in the kidney) deficiency syndromes, and most medications and acupoint therapies were focused on the "Spleen Channel" and "Kidney Channel." However, stagnation of liver Qi was mentioned less when compared with other syndromes, which did not have symptomatic medicines.

Conclusion

This study provides an in-depth perspective for the TCM syndrome differentiation, medication rules, and acupoint therapy for T2DM and provides practitioners and researchers with valuable information about the current status and frontier trends of TCM research on T2DM in terms of both diagnosis and treatment.

Effectiveness of testosterone replacement in men with obesity: a systematic review and meta-analysis

OBJECTIVE

This systematic review evaluated the effect of testosterone replacement therapy (TRT) in men with obesity having low testosterone levels (LTLs).

DESIGN AND METHODS

Search strategies were performed in MEDLINE, Embase, LILACS, and CENTRAL databases. Two reviewers selected the studies, assessed the risk of bias, and extracted data from the included studies. A random-effects model was used to pool results across studies, and the Grading of Recommendations Assessment, Development, and Evaluation was used to evaluate the certainty of evidence.

RESULTS

A total of 16 randomized controlled trials were included. With moderate certainty of the evidence, no difference was found between TRT and placebo regarding total adverse events, TRT led to a 2-kg lean body mass gain and slightly improved low-density lipoprotein (LDL), without effects on the blood pressure. Due to imprecision/heterogeneity, effects in cardiovascular events (relative risk: 0.52, 95% CI: 0.26 to 1.05, 7 trials, 583 participants), high-density lipoprotein, hematocrit, prostate-specific antigen, HbA1c, and quality of life were unclear. TRT was effective for waist circumference and BMI; however, large between-study heterogeneity was found, with 95% prediction intervals crossing the null effect line. Meta-regression revealed that the average age of participants was a significant modifier for both outcomes.

CONCLUSION

TRT slightly improved the lean body mass and LDL in men with obesity having LTLs but did not affect the blood pressure. The effects of TRT on cardiovascular events, HbA1c, and quality of life are unclear. The mean age of participants significantly modified the effect of TRT on weight loss.

Convalescent plasma as a potential management option in COVID-19: a critical review of randomized controlled registered trials

Currently, there is no approved antiviral agent to treat COVID-19. The management is based on reducing the virus spread in communities, providing supportive treatment to patients, and recently receiving immunization. In this critical review, we focus on randomized and controlled clinical trials. ClinicalTrials.gov, Chinese Clinical Trial Registry (ChiCTR), Japan Primary Registries Network (JPRN), the Australian New Zealand Clinical Trials Registry (ANZCTR), and six other Clinical Trials Registers were searched. Only randomized controlled trials covering treatment or prevention with convalescent plasma in COVID-19 patients were included. Data were extracted into summary tables. The matrix developed was used to identify common themes and compare primary and secondary outcomes of each trial against other parameters/characteristics of the trial. Microsoft Excel was used to create grids of numbers, texts and analysis using various formulae. A total of 3109 trial registry entries were identified, and 44 fulfilled the inclusion and exclusion criteria of the study. The majority of trials (n= 42, 95%) explored the therapeutic potential; only two examined prevention use. The trial's outcome measures varied and were 59 primary (median:1, IQR, 0) and 267 secondary measure outcomes (median: 6, IQR, 8). While 17 studies were recruiting for Phase 1 or 2, the remaining 16 studies were in Phase 2, and 3 and 11 studies had no phases. The total number of participants in these studies was 9432, including control groups (median: 120, IQR, 211). This review provides an overall analysis of clinical trials currently available from seventeen countries and highlights critical issues that we can learn from these trials based on available information.

Misleading Reporting (Spin) in Noninferiority Randomized Clinical Trials in Oncology With Statistically Not Significant Results: A Systematic Review

IMPORTANCE

Spin, the inaccurate reporting of randomized clinical trials (RCTs) with results that are not statistically significant for the primary end point, distorts interpretation of results and leads to misinterpretation. However, the prevalence of spin and related factors in noninferiority cancer RCTs remains unclear.

OBJECTIVE

To examine misleading reporting, or spin, and the associated factors in noninferiority cancer RCTs through a systematic review.

DATA SOURCES

A systematic search of the PubMed database was performed for articles published between January 1, 2010, and December 31, 2019, using the Cochrane Highly Sensitive Search Strategy.

STUDY SELECTION

Two investigators independently selected studies using the inclusion criteria of noninferiority parallel-group RCTs aiming to confirm effects to cancer treatments published between January 1, 2010, and December 31, 2019, reporting results that were not statistically significant for the primary end points.

DATA EXTRACTION AND SYNTHESIS

Standardized data abstraction was used to extract information concerning the trial characteristics and spin based on a prespecified definition. The main investigator extracted the trial characteristics while both readers independently evaluated the spin. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was followed.

MAIN OUTCOMES AND MEASURES

The main outcome was spin prevalence in any section of the report. Spin was defined as use of specific reporting strategies, from whatever motive, to highlight that the experimental treatment is beneficial, despite no statistically significant difference for the primary outcome, or to distract the reader from results that are not statistically significant. The associations (prevalence difference and odds ratios [ORs]) between spin and trial characteristics were also evaluated.

RESULTS

The analysis included 52 of 2752 reports identified in the PubMed search. Spin was identified in 39 reports (75.0%; 95% CI, 61.6%-84.9%), including the abstract (34 reports [65.4%; 95% CI, 51.1%-76.9%]) and the main text (38 reports [73.1%; 95% CI, 59.7%-83.3%]). Univariate analysis found that the spin prevalence was higher in reports with data managers (prevalence difference, 27%; 95% CI, 1.1%-50.3%), reports without funding from for-profit sources (prevalence difference, 31.2%; 95% CI, 4.8%-53.8%), and reports of novel experimental treatments (prevalence difference, 37.5%; 95% CI, 5.8%-64.7%). Multivariable analysis found that novel experimental treatment (OR, 4.64; 95% CI, 0.98-22.02) and funding only from nonprofit sources only (OR, 5.20; 95% CI, 1.21-22.29) were associated with spin.

CONCLUSIONS AND RELEVANCE

In this systematic review, most noninferiority RCTs reporting results that were not statistically significant for the primary end points showed distorted interpretation and inaccurate reporting. The novelty of an experimental treatment and funding only from nonprofit sources were associated with spin.

Effect of IV High-Dose Vitamin C on Mortality in Patients With Sepsis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

The aim of this study was to conduct a systematic review and meta-analysis of randomized controlled trials to investigate whether IV high-dose vitamin C improves the short-term mortality of patients with sepsis.

DESIGN

This study is a systematic review and meta-analysis of randomized controlled trials. We searched EMBASE, the Cochrane Central Register of Controlled Trials, and MEDLINE for randomized controlled trials that met inclusion criteria. The protocol was registered at the University hospital Medical Information Network Clinical Trials Registry (UMIN000040528). All analyses were presented with the use of random-effects models. The primary outcome was short-term mortality defined as 28-day, 30-day, or in-hospital mortality.

PATIENTS

Two authors independently evaluated the following eligibility criteria: 1) randomized controlled trial, 2) patients with sepsis aged ≥18 years, and 3) received intravenous high-dose vitamin C in addition to standard of care, or standard of care alone. Then, two authors independently extracted the selected patient and study characteristics and outcomes from studies that met above eligibility criteria.

MEASUREMENTS AND MAIN RESULTS

Eleven randomized controlled trials (n = 1,737 patients) were included in this meta-analysis. High-dose IV vitamin C was not associated with a significantly lower short-term mortality (risk ratio, 0.88; 95% CI, 0.73-1.06; p = 0.18; I2 = 29%) but was associated with a significantly shorter duration of vasopressor use (standardized mean difference, -0.35; 95% CI, -0.63 to -0.07; p < 0.01; I2 = 80%) and a significantly greater decline in the Sequential Organ Failure Assessment score at 72-96 hours (standardized mean difference, -0.20; 95% CI, -0.32 to -0.08; p < 0.01; I2 = 16%). One study reported significant association with hypernatremia, but adverse effects were rare, and high-dose vitamin C is deemed relatively safe.

CONCLUSIONS

In this meta-analysis, the use of IV high-dose vitamin C in patients with sepsis was not associated with lower short-term mortality although it was associated with significantly shorter duration of vasopressor use and greater decline in the Sequential Organ Failure Assessment score at 72-96 hours.

The Fragility of Statistical Significance in Cartilage Restoration of the Knee: A Systematic Review of Randomized Controlled Trials

OBJECTIVE

The purpose of this study was to utilize fragility analysis to assess the robustness of randomized controlled trials (RCTs) evaluating the management of articular cartilage defects of the knee. We hypothesize that the cartilage restorative literature will be fragile with the reversal of only a few outcome events required to change statistical significance.

DESIGN

RCTs from 11 orthopedic journals indexed on PubMed from 2000 to 2020 reporting dichotomous outcome measures relating to the management of articular cartilage defects of the knee were included. The Fragility Index (FI) for each outcome was calculated through the iterative reversal of a single outcome event until significance was reversed. The Fragility Quotient (FQ) was calculated by dividing each FI by study sample size. Additional statistical analysis was performed to provide median FI and FQ across subgroups.

RESULTS

Nineteen RCTs containing 60 dichotomous outcomes were included for analysis. The FI and FQ of all outcomes was 4 (IQR 2-7) and 0.067 (IQR 0.034-0.096), respectively. The average number of patients lost to follow-up (LTF) was 3.9 patients with 15.8% of the included studies reporting LTF greater than or equal to 4, the FI of all included outcomes.

CONCLUSIONS

The orthopedic literature evaluating articular cartilage defects of the knee is fragile as the reversal of relatively few outcome events may alter the significance of statistical findings. We therefore recommend comprehensive fragility analysis and triple reporting of the P value, FI, and FQ to aid in the interpretation and contextualization of clinical findings reported in the cartilage restoration literature.

Development and Application of the Placebo Response Model in Clinical Trials for Primary Sjögren's Syndrome

This study aimed to develop a placebo response model for pharmaceutical clinical trials of primary Sjogren's syndrome,and to quantitatively analyze the distribution and related factors influencing the placebo response to further optimize the design of clinical trials and evaluate the results of single-arm clinical trials. Public databases, including PubMed, Embase, and Cochrane Library were searched for reports on randomized placebo-controlled trials for Sjögren's syndrome which used the change from baseline in ESSDAI score as the primary outcome. The model-based meta-analysis method was used to evaluate the time course and the related influencing factors of the placebo response for ESSDAI in such clinical trials. A virtual placebo control group was constructed based on the final placebo response model to determine the treatment efficacy of belimumab and cyclosporine A for primary Sjögren's syndrome in a single-arm study. A total of 12 studies involving 450 subjects were included in the analysis. The established model described the time-course characteristics of the changes in ESSDAI score from the baseline in the 48 weeks placebo group. We found that the onset time of placebo response was approximately 12 weeks, and its efficacy plateaued at 48 weeks. The baseline ESSDAI score had a significant effect on the maximum value of the placebo response; the maximum value of the placebo response decreased by 0.552 for every 1 score rise in the baseline ESSDAI score. The efficacy of belimumab and cyclosporine A in the single-arm trial was comparable to that of the placebo response at the same baseline; no significant therapeutic advantage was observed. The placebo response model established in this study could provide a basis for designing clinical trials for primary Sjogren's syndrome in the future. It may also provide a reliable external efficacy control standard for single-arm clinical trials.

Pharmacodynamic biomarkers of long-term interferon beta-1a therapy in REFLEX and REFLEXION

This post-hoc analysis evaluated candidate biomarkers of long-term efficacy of subcutaneous interferon beta-1a (sc IFN β-1a) in REFLEX/REFLEXION studies of clinically isolated syndrome. Samples from 507 REFLEX and 287 REFLEXION study participants were analyzed. All investigated biomarkers were significantly upregulated 1.5-4-fold in response to sc IFN β-1a treatment versus baseline (p ≤ 0.008). The validity of MX1, 2'5'OAS, and IL-1RA as biomarkers of response to sc IFN β-1a was confirmed in this large patient cohort, with biomarkers consistently upregulated in a dose-dependent manner. Neopterin, TRAIL, and IP-10 were confirmed as biomarkers associated with long-term sc IFN β-1a treatment efficacy over 5 years.

Extracorporeal Shockwave Therapy for Treating Chronic Low Back Pain: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

To assess the effectiveness and safety of extracorporeal shockwave therapy (ESWT) for the treatment of chronic low back pain (CLBP).

METHODS

This was a systematic review and meta-analysis of randomized controlled trials (RCTs) designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement standard. We identified relevant studies by searching multiple electronic databases, trial registries, and websites up to April 30, 2021, and examining reference lists. We selected RCTs that compared ESWT, in unimodal or multimodal therapeutic approaches, with sham ESWT or other active therapies. Two investigators independently extracted data and assessed the risk of bias and quality of the evidence. The main outcomes were pain intensity and disability status, examined as standardized mean differences (SMD) with 95% confidence intervals (CI). The risk of bias was assessed by using Cochrane Back and Neck (CBN) Group risk of bias tool and Jadad score, and GRADE was applied to determine the confidence in effect estimates. Heterogeneity was explored using sensitivity analysis and meta-regression.

RESULTS

Ten RCTs, including a total of 455 young to middle-aged individuals (29.2-55.8 years), were identified. Compared with control, the ESWT group showed lower pain intensity at month 1 (SMD = -0.81, 95% CI -1.21 to -0.42), as well as lower disability score at month 1 (SMD = -1.45, 95% CI -2.68 to -0.22) and at month 3 (SMD = -0.69, 95% CI -1.08 to -0.31). No serious shockwave-related adverse events were reported.

CONCLUSION

The use of ESWT in CLBP patients results in significant and quantifiable reductions in pain and disability in the short term. However, further well-conducted RCTs are necessary for building high-quality evidence and promoting the application of ESWT in clinical practice.

Maggot Debridement Therapy for Chronic Leg and Foot Ulcers: A Review of Randomized Controlled Trials

OBJECTIVE

To critically analyze the existing randomized controlled trials (RCTs) on the clinical, economic, and psychological implications of maggot debridement therapy (MDT).

DATA SOURCES

An exhaustive literature search for English-language publications was conducted using MEDLINE, EMBASE, and PubMed.

STUDY SELECTION

Keywords used for the search were based on the PICO (Population, Intervention, Comparison, Outcome) framework. The titles, abstracts, and relevant full-text articles were screened. Seven RCTs were selected after applying the inclusion and exclusion criteria.

DATA EXTRACTION

Data pertaining to the primary and secondary outcomes of each study were extracted.

DATA SYNTHESIS

The data extracted were evaluated and categorized into clinical, economic, and psychological outcomes pertaining to MDT. A judicious evaluation of these outcomes was made, and the following conclusions were drawn.

CONCLUSIONS

There exists heterogeneity in the extant RCTs, but MDT appears to be effective for a quick early debridement. For diabetic foot ulcers, MDT improves debridement, controls infection, and enhances wound healing. In chronic peripheral vascular disease ulcers, it aids in early debridement, but the final outcome is equivocal. Further robust integrated health economic and parallel qualitative assessment studies are recommended to understand the cost-effectiveness and patient acceptability and experience.

Days alive out of hospital in heart failure: Insights from the PARADIGM-HF and CHARM trials

BACKGROUND

An endpoint that has received some attention in recent cardiovascular trials is 'days alive and out of hospital' (DAOH). Percent DAOH is a natural extension of DAOH that adjusts for differences in length of follow-up. This endpoint measure incorporates mortality and morbidity together in a way that has the potential to give more insight regarding treatment effects compared to conventional time-to-event endpoints. Other advantages of this measure include the relative ease of collection and interpretation. However, research on how to analyze this measure is still limited.

METHODS

We propose using the one-inflated beta model to analyze percent DAOH. This model is appropriate for highly left-skewed data with a large proportion of boundary values. Data from the Prospective Comparison of ARNI [Angiotensin Receptor-Neprilysin Inhibitor] with ACEI [Angiotensin-Converting-Enzyme Inhibitor] to Determine Impact on Global Mortality and Morbidity in Heart Failure Trial (PARADIGM-HF) and Candesartan in Heart Failure Assessment of Reduction in Mortality and morbidity (CHARM) trials are used to illustrate this method.

RESULTS

Statistically significant differences in percent DAOH were observed for PARADIGM-HF and CHARM in favor of treatment. In PARADIGM-HF, treatment with sacubitril plus valsartan increased DAOH on average by 11 days (95% CI: 1.4-20.9 days) and increased percent DAOH by 1.64% at a fixed follow-up length of 1,000 days (95% CI: 0.61%- 2.67%). For the CHARM overall program, the candesartan group has 1.79% more DAOH (95% CI: 0.91%- 2.68%).

CONCLUSION

DAOH, and especially percent DAOH, can enhance our understanding of treatment effects in future cardiovascular trials, and the one-inflated beta model is an appropriate choice for its analysis.

Glycemic control and neonatal outcomes in women with gestational diabetes mellitus treated using glyburide, metformin, or insulin: a pairwise and network meta-analysis

AIMS

We aimed to assess the comparative efficiency and safety of the use of glyburide, metformin, and insulin in gestational diabetes mellitus (GDM).

METHODS

We searched for randomized controlled trials that compared glyburide, metformin, and insulin in GDM. Data regarding glycemic control and neonatal safety were collected and analyzed in pairwise and network meta-analyses.

RESULTS

A total of 4533 individuals from 23 trials were included. Compared with glyburide, metformin reduced 2-h postprandial blood glucose (2HPG) to a greater extent (standard mean difference (SMD) 0.18; 95% credible interval (CI) 0.01, 0.34). There were significantly lower prevalence of neonatal hypoglycemia (risk difference (RD) - 0.07; 95%CI - 0.11, - 0.02) and preeclampsia (RD - 0.03; 95%CI - 0.06, 0) in the metformin group than in the insulin group. The metformin group had significantly lower birth weight (SMD - 0.17; 95%CI - 0.25, - 0.08) and maternal weight gain (SMD - 0.61; 95%CI - 0.86,- 0.35) compared with the insulin group. Network meta-analysis suggested that metformin had the highest probability of successfully controlling glycemia and preventing neonatal complications.

CONCLUSIONS

The present meta-analysis suggests that metformin may be as effective as insulin for glycemic control and is the most promising drug for the prevention of neonatal and maternal complications.

Cluster randomized trials of individual-level interventions were at high risk of bias

OBJECTIVES

To describe the prevalence of risks of bias in cluster-randomized trials of individual-level interventions, according to the Cochrane Risk of Bias tool.

STUDY DESIGN AND SETTING

Review undertaken in duplicate of a random sample of 40 primary reports of cluster-randomized trials of individual-level interventions.

RESULTS

The most common reported reasons for adopting cluster randomization were the need to avoid contamination (17, 42.5%) and practical considerations (14, 35%). Of the 40 trials all but one was assessed as being at risk of bias. A majority (27, 67.5%) were assessed as at risk due to the timing of identification and recruitment of participants; many (21, 52.5%) due to an apparent lack of adequate allocation concealment; and many due to selectively reported results (22, 55%), arising from a mixture of reasons including lack of documentation of primary outcome. Other risks mostly occurred infrequently.

CONCLUSION

Many cluster-randomized trials evaluating individual-level interventions appear to be at risk of bias, mostly due to identification and recruitment biases. We recommend that investigators carefully consider the need for cluster randomization; follow recommended procedures to mitigate risks of identification and recruitment bias; and adhere to good reporting practices including clear documentation of primary outcome and allocation concealment methods.

Association Between Lack of Blinding and Mortality Results in Critical Care Randomized Controlled Trials: A Meta-Epidemiological Study

OBJECTIVES

To investigate whether intervention effect estimates for mortality differ between blinded and nonblinded randomized controlled trials conducted in critical care. We used a meta-epidemiological approach, comparing effect estimates between blinded and nonblinded randomized controlled trials for the same research question.

DATA SOURCES

Systematic reviews and meta-analyses of randomized controlled trials evaluating a therapeutic intervention on mortality in critical care, published between January 2009 and March 2019 in high impact factor general medical or critical care journals and by Cochrane.

DATA EXTRACTION

For each randomized controlled trial included in eligible meta-analyses, we evaluated whether the trial was blinded (i.e., double-blinded and/or reporting adequate methods) or not (i.e., open-label, single-blinded, or unclear). We collected risk of bias evaluated by the review authors and extracted trial results.

DATA SYNTHESIS

Within each meta-analysis, we compared intervention effect estimates between blinded and nonblinded randomized controlled trials by using a ratio of odds ratio (< 1 indicates larger estimates in nonblinded than blinded randomized controlled trials). We then combined ratio of odds ratios across meta-analyses to obtain the average relative difference between nonblinded and blinded trials. Among 467 randomized controlled trials included in 36 meta-analyses, 267 (57%) were considered blinded and 200 (43%) nonblinded. Intervention effect estimates were statistically significantly larger in nonblinded than blinded trials (combined ratio of odds ratio, 0.91; 95% CI, 0.84-0.99). We found no heterogeneity across meta-analyses (p = 0.72; I2 = 0%; τ2 = 0). Sensitivity analyses adjusting the main analysis on risk of bias items yielded consistent results.

CONCLUSIONS

Intervention effect estimates of mortality were slightly larger in nonblinded than blinded randomized controlled trials conducted in critical care, but confounding cannot be excluded. Blinding of both patients and personnel is important to consider when possible in critical care trials, even when evaluating mortality.

Misoprostol plus isosorbide mononitrate versus misoprostol alone for cervical ripening during labor induction: A systematic review and meta-analysis of randomized controlled trials

AIM

To conduct a systematic review and meta-analysis of all randomized controlled trials (RCTs) that examined the maternal and neonatal outcomes of misoprostol+isosorbide mononitrate (ISMN) versus misoprostol alone (control) in promoting cervical ripening during labor induction.

METHODS

We searched five databases from inception until 05-May-2021. We assessed risk of bias of RCTs, meta-analyzed 23 endpoints, and pooled them as mean difference or risk ratio with 95% confidence interval.

RESULTS

Overall, five RCTs met the inclusion criteria, comprising 850 patients (426 and 424 patients were allocated to misoprostol+ISMN and misoprostol group, respectively). Overall, the RCTs had a low risk of bias. Pertaining to maternal delivery-related outcomes, there was no significant difference between both groups regarding the mean interval from drug administration to delivery, rate of vaginal delivery, rate of cesarean section delivery, and rate of need for oxytocin augmentation. Pertaining to maternal drug-related side effects, the rate of maternal headache was significantly higher in disfavor of the misoprostol+ISMN compared with misoprostol alone. However, the rates of maternal nausea, hypotension, flushing, palpitation, dizziness, postpartum hemorrhage, and uterine tachysystole did not differ between both groups. Pertaining to neonatal outcomes, there was no significant difference between both groups regarding rates of NICU admission, meconium-stained amniotic fluid, and Apgar score <7 at five minutes.

CONCLUSION

Compared with misoprostol alone, co-administration of misoprostol+ISMN did not correlate with superior maternal delivery-related outcomes. The rate of maternal headache was significantly higher in disfavor of the misoprostol+ISMN group. There was no significant difference between both groups regarding neonatal endpoints.

Xuesaitong injection treating acute myocardial infarction: A systematic review and meta-analysis

BACKGROUND

Although the incidence of acute myocardial infarction (AMI) is decreasing, the mortality in AMI patients remains substantial. Traditional Chinese medicine has shown its role in the prevention and management of AMI. The purpose of this study is to evaluate the clinical efficacy of Xuesaitong injection (XST) for the treatment of AMI by a meta-analysis.

METHODS

A literature search was performed in 5 medical databases up to June 1, 2020. Randomized controlled trials involving XST combined with conventional treatment versus conventional treatment were included. A meta-analysis of clinical efficacy, left ventricular function and other objective parameters was performed to evaluate the effects of XST on AMI.

RESULTS

Five randomized controlled trials involving 539 participants were eventually included. Meta-analysis showed that the combination of XST and conventional treatment could achieve significantly better effect on improving clinical efficacy (risk ratio: 1.09 [1.01, 1.17]; P = .04), left ventricular ejection fraction (mean difference [MD]: 3.18 [1.69, 4.67]; P < .0001), hypersensitive C-reactive protein (MD: -2.58 [-5.04, -0.12]; P = .04), interleukin 6 (MD: -26.00 [-38.85, -13.16]; P < .0001), cardiac troponin T (MD: -15.85 [-18.09, -13.61]; P < .00001) and creatine kinase myocardial isoenzyme (MD: -73.06 [-79.74, -66.37]; P < .00001).

CONCLUSION

XST combined with conventional treatment can achieve better efficacy on clinical performance and some of the AMI related parameters. However the interpretation of the results should be cautious, due to the relatively low quality of included trials. More rigorously designed, large-scaled, randomized controlled trials are warranted to support its clinical use in the future.

Modified Robert Jones Bandage in reducing blood loss in total knee arthroplasty: A meta-analysis of randomized controlled trials

BACKGROUND

The purpose of this meta-analysis was to assess the effects of Modified Robert Jones Bandage (MRJB) in primary total knee arthroplasty (TKA).

METHODS

PubMed, EMBASE, the Cochrane Library, Web of Science, and Google Scholar were systematically searched for randomized controlled trials (RCTs). All RCTs were compared to receive either MRJB (study group) or conventional wound dressing (control group) in TKA. Statistical analysis was assessed using RevMan 5.3 software.

RESULTS

A total of 5 RCTs involving 362 patients were included in the meta-analysis. No significant difference between the 2 groups was found in terms of total blood loss (Mean difference [MD], -25.41; 95% confidence interval [CI], -90.52 to 39.70; P = .44), intra-operative blood loss (MD, -13.77; 95% CI, -31.84 to 4.29; P = .14), drain blood loss (MD, 0.83; 95% CI, -30.07 to 31.72; P = .96), and transfusion rate (risk ratio, 0.95; 95% CI, 0.55-1.64; P = .86); There was also no significant difference in terms of range of motion (MD, -0.93; 95% CI, -3.64 to 1.79; P = .50), visual analog scale pain sores (MD, -0.02; 95% CI, -0.34 to 0.30; P = .90), and operative time (MD, -3.12; 95% CI, -13.42 to 7.18; P = .55), without increasing the risk of wound-related complications (risk ratio, 0.75; 95% CI, 0.27-2.08; P = .58) in both groups. No deep venous thrombosis occurred in all studies.

CONCLUSIONS

The current meta-analysis of the available evidence indicates patients with MRJB had not required the additional advantage compared to the conventional wound dressing for TKA. However, more high-quality studies are needed to confirm the above conclusions.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Efficacy and safety of dual vs single renin-angiotensin-aldosterone system blockade in chronic kidney disease: An updated meta-analysis of randomized controlled trials

BACKGROUND

To lower albuminuria and to achieve blood pressure (BP) goals, dual renin-angiotensin-aldosterone system (RAAS) inhibitors are sometimes used in clinical practice for the treatment of CKD. However, the efficacy and safety of dual RAAS blockade therapy remains controversial.

METHODS

PubMed, EMBASE, and Cochrane Library were searched, and random effects model was used to calculate the effect sizes of eligible studies. Potential sources of heterogeneity were detected by meta-regression and subgroup analysis.

RESULTS

The present meta-analysis of 72 randomized controlled trials with 10,296 patients demonstrated that dual RAAS blockade therapy was superior to monotherapy in reducing the urine albumin excretion, urine protein excretion, and BP. These beneficial effects were related to the decrease of glomerular filtration rate, the increase of serum potassium level, and higher rates of hyperkalemia and hypotension. Meanwhile, these effects did not lead to improvements in short-term or long-term outcomes, including doubling of serum creatinine, acute kidney injury, end-stage renal disease, mortality, and hospitalization. Compared with the single therapy, angiotensin-converting enzyme inhibitor (ACEI) in combination with angiotensin-receptor blocker (ARB) was a better dual therapy than ACEI or ARB in combination with renin inhibitor or aldosterone receptor antagonist in decreasing urine albumin excretion, urine protein excretion and BP, and the combination was not associated with a lower glomerular filtration rate.

CONCLUSION

Compared with the single therapy, ACEI in combination with ARB was a better dual therapy than ACEI or ARB in combination with renin inhibitor or aldosterone receptor antagonist. Although ACEI in combination with ARB was associated with higher incidences of hyperkalemia and hypotension, careful individualized management and potassium binders may further expand its application (PROSPERO number CRD42020179398).

Characteristics and Research Waste Among Randomized Clinical Trials in Gastric Cancer

IMPORTANCE

The results of numerous large randomized clinical trials (RCTs) have changed clinical practice in gastric cancer (GC). However, research waste (ie, unpublished data, inadequate reporting, or avoidable design limitations) is still a major challenge for evidence-based medicine.

OBJECTIVES

To determine the characteristics of GC RCTs in the past 20 years and the presence of research waste and to explore potential targets for improvement.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional study of GC RCTs, ClinicalTrials.gov was searched for phase 3 or 4 RCTs registered from January 2000 to December 2019 using the keyword gastric cancer. Independent investigators undertook assessments and resolved discrepancies via consensus. Data were analyzed from August through December 2020.

MAIN OUTCOMES AND MEASURES

The primary outcomes were descriptions of the characteristics of GC RCTs and the proportion of studies with signs of research waste. Research waste was defined as unpublished data, inadequate reporting, or avoidable design limitations. Publication status was determined by searching PubMed and Scopus databases. The adequacy of reporting was evaluated using the Consolidated Standards of Reporting Trials (CONSORT) reporting guideline checklist. Avoidable design limitations were determined based on existing bias or lack of cited systematic literature reviews. In the analyses of research waste, 125 RCTs that ended after June 2016 without publication were excluded.

RESULTS

A total of 262 GC RCTs were included. The number of RCTs increased from 25 trials in 2000 to 2004 to 97 trials in 2015 to 2019, with a greater increase among RCTs of targeted therapy or immunotherapy, which increased from 0 trials in 2000 to 2004 to 36 trials in 2015 to 2019. The proportion of RCTs that were multicenter was higher in non-Asian regions than in Asian regions (50 of 71 RCTs [70.4%] vs 96 of 191 RCTs [50.3%]; P = .004). The analysis of research waste included 137 RCTs, of which 81 (59.1%) were published. Among published RCTs, 65 (80.2%) were judged to be adequately reported and 63 (77.8%) had avoidable design defects. Additionally, 119 RCTs (86.9%) had 1 or more features of research waste. Study settings that included blinding (odds ratio [OR], 0.56; 95% CI, 0.33-0.93; P = .03), a greater number of participants (ie, ≥200 participants; OR, 0.07; 95% CI, 0.01-0.51; P = .01), and external funding support (OR, 0.22; 95% CI, 0.08-0.60; P = .004) were associated with lower odds of research waste. Additionally, 35 RCTs (49.3%) were referenced in guidelines, and 18 RCTs (22.2%) had their prospective data reused.

CONCLUSIONS AND RELEVANCE

To our knowledge, this study is the first to describe the characteristics of GC RCTs in the past 20 years, and it found a research waste burden, which may provide evidence for the development of rational RCTs and reduction of waste in the future.

Use of Second-line Immunotherapy in Control Arms of Randomized Clinical Trials in Kidney Cancer: A Systematic Review

IMPORTANCE

Immunotherapy (anti-programmed death ligand 1 antibodies) is associated with improved survival rates in advanced kidney cell carcinoma (KCC) after progression on first-line tyrosine kinase inhibitor (TKI) treatment. It is unknown whether and to what degree patients in the control arm receive postprotocol immunotherapy in trials comparing combination immunotherapy regimens with TKI in first-line advanced KCC.

OBJECTIVE

To characterize the proportion of patients in the control arm who received postprotocol immunotherapy in trials comparing combination immunotherapy regimens with TKI in first-line advanced KCC.

EVIDENCE REVIEW

A search of PubMed was conducted to identify randomized clinical trials of combination immunotherapy compared with TKI in first-line advanced KCC between January 1, 2015, and February 28, 2021. Combination immunotherapy was defined as an anti-programmed death ligand 1 agent and an additional agent. Search terms included renal cell cancer and first-line and were filtered by the type clinical trial. All English-language trials of combination immunotherapy compared with a TKI were included. The trials and their protocols and supplements were analyzed to determine the proportion of patients in the control arm receiving postprotocol immunotherapy.

FINDINGS

A total of 106 articles met search criteria and were screened. A total of 6 trials and 3 published updates of trial results were included in the systematic review. Of 2565 patients assigned to control arm groups, 2069 (81%) were no longer on TKI at last data cutoff. Of patients in the control arm who discontinued TKI, 932 (45%) received postprotocol immunotherapy. Of patients in the control arm receiving any type of postprotocol therapy, 66.4% received immunotherapy.

CONCLUSIONS AND RELEVANCE

This systematic review found that the proportion of patients in the control arm receiving postprotocol immunotherapy is low in randomized clinical trials of first-line combination immunotherapy regimens for advanced KCC. Appropriate use of postprotocol therapy is essential to answering the question of whether a combination or sequential treatment strategy with immunotherapy is superior.

Effectiveness of bisphosphonates on bone mineral density in osteopenic postmenopausal women: A systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Various bisphosphonate agents have been proven to be effective in preventing bone loss and fracture in osteopenic postmenopausal women. This study was designed to compare the effectiveness of various BPs on preventing the loss of bone mineral density (BMD) for postmenopausal women with osteopenia.

METHODS

PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were screened up to identify randomized controlled trails comparing effectiveness of BPs or placebo on the BMD of postmenopausal women with osteopenia. Network meta-analysis and standard pair-wise meta-analyses were performed. The main outcomes include the percentage changes of 6-, 12-, 24-, and 36-month BMD at lumbar, total hip and femoral neck, and frequencies of new fractures and severe adverse events.

RESULTS

Fourteen randomized controlled trials were eligible, involving 11,540 participants. No significant difference was presented among the available interventions for the 6-month BMD at 3 different sites, but the magnitudes of differences among the treatment regimens became gradually increased along with the extending of follow-up periods. Daily aledronate of more than 5 mg provided the maximal percentage increase on BMD of femoral neck and lumbar spine, while zoledronate provided maximal change on BMD of total hip, at different follow-up periods. This network meta-analysis also demonstrated similar frequencies of new clinical fractures and severe adverse events among different interventions.

CONCLUSIONS

A ranking spectrum depicting the effectiveness on BMD percentage change following interventions with different bisphosphonate regimens was provided. Generally, regimens with zoledronate and aledronate were found to be the most effective interventions in the 3 sites at different end points.

Optimal timing of endoscopy for acute upper gastrointestinal bleeding: a systematic review and meta-analysis

Acute upper gastrointestinal bleeding (UGIB) is the most common indication for urgent endoscopy, but the correct timing of endoscopy in these patients is still debated. Our systematic review with meta-analysis was aimed at investigating the potential clinical benefit of very early endoscopy for UGIB patients. We performed an electronic literature search of PubMed, Scopus, Web of Science and the Cochrane Library up to 23rd May 2020 and considered only randomised controlled trials (RCTs) comparing management of UGIB patients by very early vs early endoscopy. Only five RCTs were considered eligible for quantitative analysis, with a total population of 926 cases (468 in the very early endoscopy arm and 458 in the early). The meta-analysis showed no statistically significant benefit for very early endoscopy compared to early endoscopy in terms of risk of rebleeding, mortality, ICU admission, blood transfusion, surgery and length of hospital stay. However, our results showed a significantly higher need for haemostatic treatment when very early endoscopy was performed (RR 1.23, 95% CI 1.06-1.42, p < 0.01) in comparison to early endoscopy.

Comparison of treatments for the prevention of fetal growth restriction in obstetric antiphospholipid syndrome: a systematic review and network meta-analysis

Women with criteria and non-criteria obstetric antiphospholipid syndrome (APS) carry an increased risk of pregnancy complications, including fetal growth restriction (FGR). The management of obstetric APS traditionally involves clinicians, obstetricians and gynaecologists; however, the most appropriate prophylactic treatment strategy for FGR prevention in APS is still debated. We performed a systematic review and network meta-analysis (NetMA) to summarize current evidence on pharmacological treatments for the prevention of FGR in APS. We searched PubMed and Embase from inception until July 2020, for randomized controlled trials and prospective studies on pregnant women with criteria or non-criteria obstetric APS. NetMA using a frequentist framework were conducted for the primary outcome (FGR) and for secondary outcomes (fetal or neonatal death and preterm birth). Adverse events were narratively summarised. Out of 1124 citations, we included eight studies on 395 pregnant patients with obstetric APS treated with low-dose aspirin (LDA) + unfractionated heparin (UFH) (n = 132 patients), LDA (n = 115), LDA + low molecular weight heparin (n = 100), LDA + corticosteroids (n = 29), LDA + UFH + intravenous immunoglobulin (n = 7), or untreated (n = 12). No difference among treatments emerged in terms of FGR prevention, but estimates were largely imprecise, and most studies were at high/unclear risk of bias. An increased risk of fetal or neonatal death was found for LDA monotherapy as compared to LDA + heparin, and for no treatment as compared to LDA + corticosteroids. The risk of preterm birth was higher for LDA + UFH + IVIg as compared to LDA or LDA + heparin, and for LDA + corticosteroids as compared to LDA or LDA + LMWH. No treatment was associated with an increased risk of bleeding, thrombocytopenia or osteopenia.

The efficiency and safety of methimazole and propylthiouracil in hyperthyroidism: A meta-analysis of randomized controlled trials

PURPOSE

The aim of this study was to evaluate the efficiency and safety of methimazole (MMI) and propylthiouracil (PTU) in the treatment of hyperthyroidism.

METHODS

Articles were searched through the PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, Wanfang, and QVIP. The primary outcomes were clinical efficacy and thyroid hormone levels in MMI and PTU groups. The secondary outcomes were liver function indexes and adverse reactions in MMI and PTU groups. Results were expressed as weighted mean difference (WMD) or odds ratio (OR) with 95% confidence intervals (CIs). The Begg test was applied to assess the publication bias.

RESULTS

Totally, 16 randomized controlled trials were retained in this meta-analysis with 973 patients receiving MMI and 933 receiving PTU. The levels of triiodothyronine (T3) (WMD = -1.321, 95% CI: -2.271 to -0.372, P = .006), thyroxine (T4) (WMD = -37.311, 95% CI: -61.012 to -13.610, P = .002), Free T3 (FT3) (WMD = -1.388, 95% CI: -2.543 to -0.233, P = .019), Free T4 (FT4) (WMD = -3.613, 95% CI: -5.972 to -1.255, P = .003), and the risk of liver function damage (OR = 0.208, 95% CI: 0.146-0.296, P < .001) in the MMI group were lower than those in the PTU group. The thyroid-stimulating hormone level (WMD = 0.787, 95% CI: 0.380-1.194, P < .001) and the risk of hypothyroidism (OR = 2.738, 95% CI: 1.444-5.193, P = .002) were higher in the MMI group than those in the PTU group.

CONCLUSIONS

Although MMI might have higher risk of hypothyroidism than PTU, the efficacy of MMI may be better than PTU in patients with hyperthyroidism regarding reducing T3, T4, FT3, and FT4 levels, decreasing the risk of liver function damage and increasing the level of thyroid-stimulating hormone.

REGISTER NUMBER

osf.io/ds637 (https://osf.io/search/).

A Bayesian analysis of mortality outcomes in multicentre clinical trials in critical care

BACKGROUND

Multicentre RCTs are widely used by critical care researchers to answer important clinical questions. However, few trials evaluating mortality outcomes report statistically significant results. We hypothesised that the low proportion of trials reporting statistically significant differences for mortality outcomes is plausibly explained by lower-than-expected effect sizes combined with a low proportion of participants who could realistically benefit from studied interventions.

METHODS

We reviewed multicentre trials in critical care published over a 10-yr period in the New England Journal of Medicine, the Journal of the American Medical Association, and the Lancet. To test our hypothesis, we analysed the results using a Bayesian model to investigate the relationship between the proportion of effective interventions and the proportion of statistically significant results for prior distributions of effect size and trial participant susceptibility.

RESULTS

Five of 54 trials (9.3%) reported a significant difference in mortality between the control and the intervention groups. The median expected and observed differences in absolute mortality were 8.0% and 2.0%, respectively. Our modelling shows that, across trials, a lower-than-expected effect size combined with a low proportion of potentially susceptible participants is consistent with the observed proportion of trials reporting significant differences even when most interventions are effective.

CONCLUSIONS

When designing clinical trials, researchers most likely overestimate true population effect sizes for critical care interventions. Bayesian modelling demonstrates that that it is not necessarily the case that most studied interventions lack efficacy. In fact, it is plausible that many studied interventions have clinically important effects that are missed.

The effect of exercise training on blood pressure in menopause and postmenopausal women: A systematic review of randomized controlled trials

The prevalence of hypertension is higher in postmenopausal than in premenopausal women. Regular exercise training has been shown to be effective in addressing hypertension. The aim of this systematic review was to synthesize the effect of exercise training on systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) in menopausal and postmenopausal women. This review was reported according to the PRISMA statement and registered in PROSPERO. The literature search was done in MEDLINE, Embase, Cochrane CENTRAL and ClinicalTrials. Randomized controlled trials involving menopausal and postmenopausal women undergoing exercise training were included. Two blinded reviewers assessed risk of bias in the included studies by using the Cochrane Risk of Bias tool. A random-effects model was used for all analyses. Significance was set at P < 0.05. Compared with the control group, exercise training resulted in clinically significant reductions on SBP (MD -3.43 mmHg; 95% CI, -5.16, -1.71; P < 0.0001), DBP (MD, -2.25 mmHg; 95% CI, -3.40, -1.11; P = 0.0001) and MAP (MD, -3.48 mmHg; 95% CI, -5.84, -1.11; P = 0.004). Aerobic training (AT) did not produce a significant reduction in SBP, DBP and MAP (P >0.05). Combined training (CT) generated larger reductions. Exercise training generated small but clinically relevant reductions in SBP, DBP and MAP in menopausal and postmenopausal women, younger or older than 65 years, with prehypertension or hypertension. AT did not lead to a clinically relevant improvement in blood pressure (BP) in this population. In addition, CT showed the largest reductions in SBP, DBP and MAP.

Sodium-glucose cotransporter 2 inhibitors as an add-on therapy to insulin for type 1 diabetes mellitus: Meta-analysis of randomized controlled trials

AIMS

The aim was to systematically review the efficacy and safety of sodium-glucose cotransporter inhibitor (SGLT2i) as an adjunct to insulin at different follow-up durations in randomized, double-blind clinical trials in patients with type 1 diabetes.

METHODS

We conducted a search on Medline, Embase, and the Cochrane Library for relevant studies published before May 2020. According to the duration of follow-up, the subgroup analysis included four periods: 1-4, 12-18, 24-26, and 52 weeks. In the five trials included both 24-26 and 52 weeks of follow-up, we compared the efficacy by the placebo-subtracted difference and changes in SGLT2i groups.

RESULTS

Fifteen trials including 7109 participants were analyzed. The combination of SGLT2i and insulin improved hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), daily insulin dose, body weight, and blood pressure, which varied greatly by different follow-ups. Compared with %HbA1c at 24-26 weeks, placebo-subtracted differences and changes in the SGLT2i groups slightly increased. SGLT2i plus insulin treatment showed no difference in the occurrence of urinary tract infections (UTIs), hypoglycemia, or severe hypoglycemia but increased the risk of genital tract infections (GTIs) in a duration-dependent manner. SGLT2i treatment was associated with a significantly higher rate of ketone-related SAEs and diabetic ketoacidosis (DKA) at 52 weeks.

CONCLUSION

SGLT2i as an add-on therapy to insulin improved glycemic control and body weight and decreased the required dose of insulin without increasing the risk of hypoglycemia. However, after 6 months the benefits of SGLT2is on glycemic control may weaken and the risks of GTIs and DKA increased.

General Health Checks in Adult Primary Care: A Review

IMPORTANCE

General health checks, also known as general medical examinations, periodic health evaluations, checkups, routine visits, or wellness visits, are commonly performed in adult primary care to identify and prevent disease. Although general health checks are often expected and advocated by patients, clinicians, insurers, and health systems, others question their value.

OBSERVATIONS

Randomized trials and observational studies with control groups reported in prior systematic reviews and an updated literature review through March 2021 were included. Among 19 randomized trials (906 to 59 616 participants; follow-up, 1 to 30 years), 5 evaluated a single general health check, 7 evaluated annual health checks, 1 evaluated biannual checks, and 6 evaluated health checks delivered at other frequencies. Twelve of 13 observational studies (240 to 471 415 participants; follow-up, cross-sectional to 5 years) evaluated a single general health check. General health checks were generally not associated with decreased mortality, cardiovascular events, or cardiovascular disease incidence. For example, in the South-East London Screening Study (n = 7229), adults aged 40 to 64 years who were invited to 2 health checks over 2 years, compared with adults not invited to screening, experienced no 8-year mortality benefit (6% vs 5%). General health checks were associated with increased detection of chronic diseases, such as depression and hypertension; moderate improvements in controlling risk factors, such as blood pressure and cholesterol; increased clinical preventive service uptake, such as colorectal and cervical cancer screening; and improvements in patient-reported outcomes, such as quality of life and self-rated health. In the Danish Check-In Study (n = 1104), more patients randomized to receive to a single health check, compared with those randomized to receive usual care, received a new antidepressant prescription over 1 year (5% vs 2%; P = .007). In a propensity score-matched analysis (n = 8917), a higher percentage of patients who attended a Medicare Annual Wellness Visit, compared with those who did not, underwent colorectal cancer screening (69% vs 60%; P < .01). General health checks were sometimes associated with modest improvements in health behaviors such as physical activity and diet. In the OXCHECK trial (n = 4121), fewer patients randomized to receive annual health checks, compared with those not randomized to receive health checks, exercised less than once per month (68% vs 71%; difference, 3.3% [95% CI, 0.5%-6.1%]). Potential adverse effects in individual studies included an increased risk of stroke and increased mortality attributed to increased completion of advance directives.

CONCLUSIONS AND RELEVANCE

General health checks were not associated with reduced mortality or cardiovascular events, but were associated with increased chronic disease recognition and treatment, risk factor control, preventive service uptake, and improved patient-reported outcomes. Primary care teams may reasonably offer general health checks, especially for groups at high risk of overdue preventive services, uncontrolled risk factors, low self-rated health, or poor connection or inadequate access to primary care.

Comparison of insulin glargine 300 U/mL versus glargine 100 U/mL on glycemic control and hypoglycemic events in East Asian patients with type 2 diabetes: A Patient-level meta-analysis of phase 3 studies

AIMS

To evaluate efficacy and safety of Gla-300 with Gla-100 in a patient-level meta-analysis among large East Asian patients with type 2 diabetes mellitus (T2DM).

METHODS

A patient level meta-analysis of three EDITION studies with similar design and endpoints were conducted over 6-months treatment period. The analysis included 547 patients treated with Gla-300 and 348 patients treated with Gla-100.

RESULTS

Over 6-month treatment period, mean change in HbA1c was similar for Gla-300 [Least square (LS) mean, (SE): -1.13 (0.05) % and Gla-100: -1.14 (0.05) %], showing non-inferiority of Gla-300 to Gla-100 (LS mean difference: 0.02%, 95% CI: -0.08 to 0.11). Gla-300 was associated with reduced risk of hypoglycemic event (confirmed ≤ 3.9 mmol/L or severe) vs Gla-100 at any time of day or at night (00:00-05:59 h). The event rates of hypoglycemia were consistently lower with Gla-300 than Gla-100. Severe hypoglycemia was rare in both treatment groups. Weight gain was minimal in both treatment groups.

CONCLUSION

Gla-300 provides comparable glycemic control to Gla-100 in East Asian patients with broad clinical spectrum of T2DM, with consistently less hypoglycemia at any time of the day and night.

Glaucoma Publication Trends in Leading General Ophthalmology Journals During the Past Quarter Century: Where Are the Clinical Trials?

PRCIS

During the past quarter century, the rate of glaucoma-related publication in general ophthalmology journals increased due to higher representation in "experimentally oriented" journals. The rate of glaucoma randomized controlled clinical trial (RCT) articles decreased during the same time period.

PURPOSE

To evaluate trends in rate of glaucoma publications in leading general ophthalmology journals over the past quarter century.

MATERIALS AND METHODS

Q1 ophthalmology journals Web sites were reviewed. Only journals not limited to certain subspecialty were considered "general" and included in the analysis. In addition we categorized journals orientation as either "clinical" or "experimental." The PubMed search engine was used to collect publications from the selected journals between January 1, 1995 to December 31, 2019. Publications captured by "glaucoma" or "ocular hypertension" filters were considered glaucoma related. The fraction of glaucoma articles out of total number of articles within each year for each journal was calculated. A linear mixed effects model was applied to detect trends in glaucoma publication rates during the study period.

RESULTS

Eight journals were included: 4 "clinically oriented" and 4 "experimentally oriented." The PubMed search yielded 72,750 publications, of which 9329 (12.8%) considered "glaucoma related." Percentage of glaucoma publications remained stable within "clinically oriented" journals, and significantly increased within "experimentally oriented" journals (annual change of 0.3%, P<0.001). The number of glaucoma-related RCTs decreased significantly in each (annual change of -0.21% and -0.13%, respectively, P<0.05).

CONCLUSIONS

There has been a significant rise in the rates of glaucoma publications in "experimentally oriented" journals, while their representation in "clinically oriented" journals remained stable over the past quarter century. This change might be due to the increasing efforts to develop more advanced methods for evaluation and treatment in glaucoma, although still unable to address clinical demands. The decrease in glaucoma-related RCT articles might indicate reduced funding for such research.

Characteristics of Randomized Clinical Trials in Surgery From 2008 to 2020: A Systematic Review

IMPORTANCE

Randomized clinical trials (RCTs) provide the highest level of evidence to evaluate 2 or more surgical interventions. Surgical RCTs, however, face unique challenges in design and implementation.

OBJECTIVE

To evaluate the design, conduct, and reporting of contemporary surgical RCTs.

EVIDENCE REVIEW

A literature search performed in the 2 journals with the highest impact factor in general medicine as well as 6 key surgical specialties was conducted to identify RCTs published between 2008 and 2020. All RCTs describing a surgical intervention in both experimental and control arms were included. The quality of included data was assessed by establishing an a priori protocol containing all the details to extract. Trial characteristics, fragility index, risk of bias (Cochrane Risk of Bias 2 Tool), pragmatism (Pragmatic Explanatory Continuum Indicator Summary 2 [PRECIS-2]), and reporting bias were assessed.

FINDINGS

A total of 388 trials were identified. Of them, 242 (62.4%) were registered; discrepancies with the published protocol were identified in 81 (33.5%). Most trials used superiority design (329 [84.8%]), and intention-to-treat as primary analysis (221 [56.9%]) and were designed to detect a large treatment effect (50.0%; interquartile range [IQR], 24.7%-63.3%). Only 123 trials (31.7%) used major clinical events as the primary outcome. Most trials (303 [78.1%]) did not control for surgeon experience; only 17 trials (4.4%) assessed the quality of the intervention. The median sample size was 122 patients (IQR, 70-245 patients). The median follow-up was 24 months (IQR, 12.0-32.0 months). Most trials (211 [54.4%]) had some concern of bias and 91 (23.5%) had high risk of bias. The mean (SD) PRECIS-2 score was 3.52 (0.65) and increased significantly over the study period. Most trials (212 [54.6%]) reported a neutral result; reporting bias was identified in 109 of 211 (51.7%). The median fragility index was 3.0 (IQR, 1.0-6.0). Multiplicity was detected in 175 trials (45.1%), and only 35 (20.0%) adjusted for multiple comparisons.

CONCLUSIONS AND RELEVANCE

In this systematic review, the size of contemporary surgical trials was small and the focus was on minor clinical events. Trial registration remained suboptimal and discrepancies with the published protocol and reporting bias were frequent. Few trials controlled for surgeon experience or assessed the quality of the intervention.