Reporting Quality of Noninferiority Randomized Controlled Trials for Skin Disease: A Meta-Epidemiological Study

Noninferiority randomized controlled trials (NI-RCTs) aim to demonstrate that an intervention has acceptable efficacy compared with an established treatment. We assessed the reporting quality of NI-RCTs evaluating treatments for skin conditions. We searched MEDLINE and Embase from inception to April 2024 for NI-RCTs published in top journals measured by h5-index. Screening, full-text review, and data extraction were conducted independently in duplicate. We measured items reported from the Consolidated Standards of Reporting Trials extension for NI-RCTs published after 2006. We included 71 NI-RCTs reporting, on average, 78% of overall and 67% of NI-RCT-specific items. Forty-seven (51.6%) studies reported the noninferiority hypothesis. Sixty-five (91.5%) studies reported a noninferiority margin, with 26 (36.6%) providing justification; 48 (67.6%) calculated sample size using the margin. Twenty-two (31.0%) studies conducted both intention-to-treat and per-protocol analyses, whereas 26 (36.6%) used intention to treat, and 11 (15.5%) used per protocol alone. For 17 studies (24.0%), reviewers reached conclusions different from those of authors (7%) or could not assess appropriateness of authors' conclusions owing to insufficient reporting (17.0%). Reporting of NI-RCTs for skin conditions is inconsistent, with crucial information missing from many publications. Improved reporting is essential to incorporating their results into clinical practice.