A group of experts has developed a checklist and flow diagram called the CONSORT Statement. The checklist is designed to help authors in the reporting of randomised controlled trials (RCTs). This systematic review aims to determine whether the CONSORT Statement has made a difference to the completeness of reporting of RCTs. Reporting of RCTs published in journals that encourage authors to use the CONSORT Statement with those that do not is compared. We found that some items in the CONSORT Statement were fully reported more often when journals encouraged the use of CONSORT. While the majority of items are reported more often when journals endorse CONSORT, the data only showed a statistically significant improvement in reporting for five of 27 items. No items suggest that CONSORT decreases the completeness of reporting of RCTs published in medical journals.
None of the evaluations included in this review used experimental designs, and their methodological approaches were mostly poorly described and variable when they were described. Furthermore, evaluations assessed the completeness of reporting of RCTs within a wide range of medical fields and in journals with a wide variation in the enforcement of CONSORT endorsement. Our results do have some limitations, but given the number of included evaluations and the number of assessed RCTs, we conclude that while most RCTs are incompletely reported, the CONSORT Statement beneficially influences their reporting quality.