ABSTRACT
Objective: To assess how inadequate reporting of cointerventions influences estimated treatment effects in recent cardiovascular trials. Methods: Medline/Embase were systematically searched from January 1, 2011 to July 1, 2021 for trials evaluating pharmacologic interventions on clinical cardiovascular outcomes published in 5 high-impact journals. Information on adequate vs inadequate reporting of cointerventions, blinding, risk of bias due to deviations of intended interventions (low vs high/some concerns), funding (nonindustry vs industry), design (superiority vs noninferiority), and results were assessed by 2 reviewers. The association with effect sizes was assessed using meta-regression random-effect analysis, expressed as ratios of odds ratios (ROR). RORs of >1.0 indicated that trials with the methodological factor pointing to lower quality report larger treatment estimates. Results: In total, 164 trials were included. Of the 164 trials, 124 (74%) did not adequately report cointerventions; 89 of the 164 trials (54%) provided no information regarding cointerventions, and 70 of the 164 (43%) were at risk of bias due to inadequate blinding. Moreover, 86 of the 164 (53%) were at risk of bias due to deviation of intended interventions. Of the 164 trials, 144 (88%) were funded by the industries. Trials with inadequate reporting of cointerventions had larger treatment estimates for the primary end point (ROR, 1.08; 95% CI, 1.01-1.15; I2=0%). No significant association with results for blinding (ROR, 0.97; 95% CI, 0.91-1.03; I2=66%), deviation of intended interventions (ROR, 0.98; 95% CI, 0.92-1.04; I2=0%), or funding (ROR, 1.01; 95% CI, 0.93-1.09; I2=0%) was found. Conclusion: We conclude that trials with inadequate reporting of cointerventions showed larger treatment effect estimates, potentially indicating overestimation of therapeutic benefit. Trial Registration: Prospero Identifier: CRD42017072522.
ABSTRACT
OBJECTIVES: To compare noninferiority margins defined in study protocols and trial registry records with margins reported in subsequent publications. STUDY DESIGN AND SETTING: Comparison of protocols of noninferiority trials submitted 2001 to 2005 to ethics committees in Switzerland and The Netherlands with corresponding publications and registry records. We searched MEDLINE via PubMed, the Cochrane Controlled Trials Register (Cochrane Library issue 01/2012), and Google Scholar in September 2013 to identify published reports, and the International Clinical Trials Registry Platform of the World Health Organization in March 2013 to identify registry records. Two readers recorded the noninferiority margin and other data using a standardized data-abstraction form. RESULTS: The margin was identical in study protocol and publication in 43 (80%) of 54 pairs of study protocols and articles. In the remaining pairs, reporting was inconsistent (five pairs, 9%), or the noninferiority margin was either not reported in the publication (five pairs, 9%) or not defined in the study protocol (one pair). The confidence interval or the exact P-value required to judge whether the result was compatible with noninferior, inferior, or superior efficacy was reported in 43 (80%) publications. Complete and consistent reporting of both noninferiority margin and confidence interval (or exact P-value) was present in 39 (72%) protocol-publication pairs. Twenty-nine trials (54%) were registered in trial registries, but only one registry record included the noninferiority margin. CONCLUSION: The reporting of noninferiority margins was incomplete and inconsistent with study protocols in a substantial proportion of published trials, and margins were rarely reported in trial registries.
