Prospective registration of systematic reviews – the PROSPERO intiative

In the world of randomised controlled trials (RCTs), a number of initiatives have existed for some time to attempt to improve methodological quality and reporting.  Amongst the most important of these have been the CONSORT statement for the reporting of RCTs, and initiatives for the prospective registration of clinical trials such as the ISRCTN.  More recently, efforts have extended to the reporting of systematic reviews, with the PRISMA statement mirroring the CONSORT statement for the reporting of systematic reviews.  The Cochrane Collaboration have been providing tools and support for health care researchers undertaking systematic reviews for some time, including the registration of review protocols, but until now there has been no attempt to mirror the ISRCTN database in prospectively registering all systematic reviews, whether Cochrane reviews or otherwise.

Now the Centre for Reviews and Dissemination at the National Institute for Health Research have begun an initiative to prospectively register systematic reviews in an international register (PROSPERO).  Registration is free and there is a structured minimum dataset required for registration of a review protocol that ensures that standards are met.  Registered trials are given a unique identifier.

Prospective registration of systematic reviews is important for a number of reasons.  Most importantly, it means that any deviation for the published protocol can be questioned and must be explained, reducing the risk of bias caused by modification of the review protocol during the course of the review process.  It also provides an online database of reviews in progress to prevent duplication of efforts or to enable other researchers to identify in-progress reviews relevant to their field.  The structured format of the protocol helps to ensure that the finished review will adhere to the PRISMA guidelines for reporting of reviews.

We will be using the PROSPERO site in future to prospectively register our reviews here at the CET, and would encourage all researchers in the field of evidence based medicine to support this initiative.  It is entirely possible that at some point in the future, as with RCTs, journal editors will require evidence of a prospectively published public protocol for the review before publication is considered.