An international registry of systematic-review protocols

Support for prospective registration of protocols for systematic reviews has been gathering momentum. The PRISMA statement, a guideline for reporting systematic reviews and meta-analyses of studies that evaluate health-care interventions, advocates registration. Well-conducted systematic reviews are accepted as the best-quality evidence to inform policy and practice, and the dramatic upward trend in the number of systematic reviews published annually (fi gure) is set to continue. However, there is currently no single facility for identifying this type of research in advance of the appearance of the results of the review. There is concern about and evidence of publication and selective outcome-reporting biases associated with systematic reviews. An open registry of reviews captured at the protocol stage would facilitate good practice in systematic reviews by providing transparency of the review process and outcomes. Discrepancies between the methods of the published review and those planned in the registered protocol could be more readily identifi ed. Registration might also encourage full publication of the review’s fi ndings and transparency in changes to methods that could bias fi ndings. In both the prevention and revelation of potential bias, registration should improve quality and increase confi dence that policy or practice informed by the fi ndings of systematic reviews are indeed drawing on best-quality evidence. A registry of protocols of systematic reviews could assist those planning new reviews and updating existing ones. Easy access to information about ongoing reviews should help to optimise the use of fi nite resources by enabling funding and commissioning agencies to avoid unnecessary duplication and encourage collaboration. A comprehensive registry could also create opportunities for methodological and other research, both within and across disciplines. Existing access to systematic-review protocols is limited to the outputs of individual organisations, such as the Cochrane and Campbell Collaborations and the Joanna Briggs Institute. The National Public Health Service for Wales is piloting an All Wales Systematic Reviews Register, but, up to now, there has been no centralised comprehensive registry of systematic-review protocols. We are developing an international facility to register the details of ongoing systematic reviews in health and social care. Our registry is being established with the existing platform and infrastructure that supports the Database of Abstracts of Reviews of Eff ects (DARE), the NHS Economic Evaluations Database (NHS EED) and the Health Technology Assessment (HTA) database produced by the Centre for Reviews and Dissemination. The initial scope of the registry will be limited to systematic reviews of the eff ectiveness of health interventions. However, the longterm aim is for the registry to include details of all ongoing systematic reviews with a health-related outcome in the broadest sense. Ultimately, inclusion will encompass systematic reviews of health-care interventions, and reviews of the social determinants of health, of service delivery, and of risk factors and genetic associations. Our web-based registry will off er free public access, be electronically searchable, and open to all prospective registrants. Registration will require the provision of a minimum dataset, the completeness of which will be checked automatically before registration. After acceptance, the registry’s entry and protocol for the review, if available, will be loaded on the database as a permanent entry and a unique identifi cation number issued. An audit trail for any amendments to the information will be available within the record. Links to resulting publications will be added. These provisions ensure that the registry will match the relevant criteria required of clinical trials registries.