A systematic review of the quality of reporting and risk of bias for randomized crossover trials in digestive disease journals

BACKGROUND: The quality of randomized crossover studies on digestive diseases is unclear. We aimed to review crossover trials in digestive disease journals and evaluate their reporting quality and risk of bias. METHODS: We searched the PubMed, Web of Science, and Scopus databases for all crossover trials in 39 digestive journals between January 2011 and September 2021. Reporting adherence was based on the CONSORT 2010 statement: extension to randomized crossover trials published in July 2019. A newly released Cochrane risk of bias tool 2.0 extension for crossover trials was applied to assess the risk of bias. RESULTS: In total, 173 studies were included in the analysis, and 16.2% were published following the CONSORT statement extension. The crossover design was not only widely used in drug efficacy trials (48.6%) but also in endoscopic ultrasound trials (23.7%) and dietary studies (17.9%) in the field of digestive diseases. The overall reporting adherence was 37.6% for full texts and 43.4% for abstracts. The proportions of trials with low, some concerns, and high risk of bias were 13.9%, 15.6%, and 70.5%, respectively. The difference in reporting adherence and high risk of bias between pre- and post-CONSORT was not significant. Having a sample size plan, defining primary end points, and pre-registration showed higher reporting adherence and lower risk of bias than those who did not. CONCLUSION: These findings demonstrated the inadequate quality of randomized crossover trials for digestive diseases. Compliance with the CONSORT extension for crossover trials must be strengthened and improved (PROSPERO CRD: 42021248723).