The reporting quality of meta-analyses improves: a random sampling study

OBJECTIVES: To determine the overall quality of reporting of meta-analyses (QUOROMs) of randomized controlled trials (RCTs) based on the QUOROM statement, to compare the reporting quality of paper-based articles and Cochrane reviews, and to determine whether compliance with the statement improves over time. STUDY DESIGN AND SETTING: A random sample of systematic reviews or meta-analyses of RCTs was selected from Medline (2000-2005). RESULTS: A total of 161 articles were included. The mean QUOROM score was 12.3 (95% confidence interval [CI]: 12.0, 12.6), which rose from 10.5 (95% CI: 8.8, 12.1) in 2000 to 13.0 (95% CI: 12.2, 13.8) in 2005. The mean QUOROM scores of Cochrane reviews and paper-based articles were 14.2 (95% CI: 13.9, 14.5) and 11.7 (95% CI: 11.3, 12.1), respectively. Compared with the paper-based articles, the Cochrane reviews had better reporting quality in the abstract section, while the quality of their trial flows was poor. The fulfillment of most QUOROM items improved with time. A linear relation of the QUOROM score with time was revealed. CONCLUSIONS: The reporting quality of meta-analyses improves with time. The reporting quality of Cochrane reviews is better compared with paper-based articles. Room still exists for improvements in the reporting quality of both Cochrane and paper-based articles.