Once you have defined your review question, you should begin by searching for previously conducted systematic reviews in your area of interest.

This has three main purposes:

1.  Verify that your research question has not already been answered recently.

(*The general rule is if an SLR is less than 2 years old it is current, while something 2+ years old would be considered viable for an update)

2. Verify that there are no other review protocols registered with researchers already asking the same question

3. Identify related systematic reviews so that you can review their reference lists to scope out primary studies that were used.

Cochrane Collaboration

The Cochrane Collaboration is a not-for-profit organisation with collaborators from over 120 countries working together to promote evidence-informed health decision-making by producing high-quality, relevant, accessible systematic reviews and other synthesised research evidence.

Campbell Library

The Campbell Collaboration maintains and disseminates systematic reviews in education, crime and justice, social welfare, and international development.

PROSPERO

PROSPERO is an international database of prospectively registered systematic reviews in health and social care. Key features from the review protocol are recorded and maintained as a permanent record. PROSPERO aims to provide a comprehensive listing of systematic reviews registered at inception to help avoid unplanned duplication and enable comparison of reported review methods with what was planned in the protocol.

PubMed Clinical Queries

Clinical Queries offers a user-friendly approach to evidence-based searching on the Medline database. This tool uses predefined filters to help you quickly refine searches on clinical or disease-specific topics.

Database of Abstracts of Reviews of Effects (DARE)

The Database of Abstracts of Reviews of Effects (DARE) contains details of systematic reviews that evaluate the effects of healthcare interventions and the delivery and organisation of health services. DARE also contains reviews of the wider determinants of health such as housing, transport, and social care where these impact directly on health, or have the potential to impact on health.

Epistemonikos

Epistemonikos is a collaborative, multilingual database of health evidence. It is the largest source of systematic reviews relevant for health-decision making, and a large source of other types of scientific evidence.

JBI Evidence Synthesis

JBI Evidence Synthesis seeks to disseminate rigorous, high-quality research that provides the best available evidence to inform policy and practice through the science and conduct of systematic and scoping reviews.