Reporting quality was suboptimal in a systematic review of randomized controlled trials with adaptive designs

The study was conducted to evaluate the reporting quality of randomized controlled trials (RCTs) that use an adaptive design (AD) based on the 2020 AD Consolidated Standards for Reporting Trials 2010 extension (ACE) guidelines and identify factors associated with better reporting quality.

PubMed, Embase, Cochrane, Web of Science, and Google Scholar were searched until November 1, 2022. Multivariable linear regression analysis was performed to investigate potential predictors.

In total, 109 RCTs were included in our study. The mean compliance rate for the ACE checklist items was 69.75% ± 16.02. Key methodological items including allocation concealment and its implementations were poorly reported. There was also suboptimal reporting of checklist items related to the conduct of interim analyzes. Multivariable regression analysis showed better reporting quality with trial registration, nonindustry affiliation (first author), a sample size of >100, general medical journal type, publication date (≥2020), funding, and disclosure of the number of interim analyzes.

Our study showed that RCTs with AD had suboptimal reporting of 2020 ACE checklist items, particularly AD-specific items. Following the development of ACE guidelines, stricter adherence to the ACE guideline is necessary to improve their reporting quality. Pre-ACE and post-ACE adherence comparisons can be conducted in the future.