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Evidence‐based medicine has changed clinical practice by incorporating data from randomised controlled trials (RCTs). While some biases in RCTs are well recognised, we discuss some less acknowledged. Selection bias may arise in the consent stage. Industry‐funded studies more often report a positive outcome. Post‐hoc changes of outcome measures and other mis‐reporting lowers the reliability of outcome data. Finally, even the GRADE system retains subjectivity. Conclusion: Moving from "intuition" into "evidence‐based" medicine involves grappling with several pitfalls. These pose challenges for authors, editors, reviewers, and readers. All require vigilance before drawing conclusions from presented data. [ABSTRACT FROM AUTHOR]

Context: Randomized controlled trials (RCTs) are among the cornerstones for generation of high-quality clinical evidence. However, incomplete or biased reporting of trials can hamper the process of review of trials and their results. Outcome switching, intentional, or otherwise leads to biased reporting and can result in false inferences. Aims: The aim of this study was to analyze the completeness of reporting Consolidated Standards of Reporting Trials (CONSORT) 2010 checklist items and detect if outcome switching had occurred. Settings and Design: This cross-sectional study was conducted in the department of pharmacology. Methods: Online editions of journals published by the Indian association of medical specialties from 2017 to 2019 were accessed, and the full-text versions of the published RCTs in them were downloaded. Reporting of each item in the CONSORT checklist was recorded. The effect of trial registration and CONSORT endorsement on reporting of key methodological parameters was also determined. Protocols of registered trials were accessed, and the outcome switching was assessed. Statistical Analysis Used: Descriptive statistics were used to summarize the data. Results: Average completeness of reporting has significantly improved from 2017 to 2019. Major areas of underreporting were generalizability, protocol availability, trial registration, date of recruitment, allocation concealment, and the patient flow diagram. CONSORT endorsing journals had worse, whereas registered trials had better reporting of key methodological indicators. No overt switching of outcomes was observed in 84 out of 86 registered trials where trial protocols were available online for comparison. Conclusions: Quality of clinical trial reporting in the Indian medical journals has improved but remains inadequate. CONSORT nonendorsement prevents completeness of trial reporting. [ABSTRACT FROM AUTHOR]

Background: Progestogens have been evaluated in numerous trials and meta-analyses, many of which concluded they were effective. However, two large trials PROMISE and OPPTIMUM have recently concluded that progesterone was ineffective. This raises the possibility that earlier studies and reviews had been biased by either selective publication or selective choice of outcomes, so called "P-hacking".Objectives: To compare the findings all progestogen trials and systematic reviews with those of trials with pre-registered primary outcomes which avoided selective outcome reporting.Search Strategy: Search of PubMed, the Cochrane Library and trial registries. Registration PROSPERO CRD42016035303.Selection Criteria: Systematic reviews of randomised trials comparing progestogen with placebo in pregnancy and the individual trials included in those reviews. The subset of trials reporting a pre-registered primary outcome were compared with the totality of trials and reviews.Data Collection and Analysis: For reviews all outcomes were included. For individual trials all outcomes reported in the systematic reviews were included. For the comparison group we recorded the registered primary outcome from trials that were either registered before they started, or registered during the recruitment phase and also double blind.Main Results: Nineteen of twenty-nine meta-analyses concluded that progestogens were effective. Twenty-two trials reported their pre-registered primary outcomes. There was no effect of progesterone on primary registered dichotomous outcome RR 1.00 (95% CI 0.94-1.07). Only one of the 22 showed a nominally statistically significant benefit.Author's Conclusions: When evaluated in registered double-blind trials with analysis restricted to predefined primary outcomes, progestational agents in pregnancy are ineffective.Tweetable Abstract: Progestogens to prevent pregnancy loss, an example of P-hacking. [ABSTRACT FROM AUTHOR]