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Systematic Reviews and Meta Analysis

A resource for finding data sources, filters, and standards to support systematic searches of the biomedical literature.

Data Sources

Databases You Will Probably Search

Reviews and readers will expect these databases to be searched in most systematic literature reviews.  You'll need a reason not to search them.

  • PubMed (MEDLINE)
    Start your search here.  MeSH is useful for nucleating search concepts.
  • Embase
    Note: Embase requires users to either create an individual account (free) or log in with an institutional email address to enable the export of records. Before you start a session, 'log in" at the upper right. You can either create an account or use your Harvard email (recommended). Approximately 85% overlap with MEDLINE with more second tier European and Asian journals. Has some meetings.  EMTREE controlled vocabulary can be adapted from MeSH terms.
  • Cochrane Library (Includes the Cochrane Central Register of Controlled Trials)
    Cochrane Central contains MEDLINE trials plus many trials from other, non-indexed sources; limited to randomized and non-randomized controlled trials.  MeSH for MEDLINE records, but no other controlled vocabulary. To limit to results in Central, click the "Trials" limit to the left of your results.
  • Web of Science (Science Citation Index)
    Broad but not deep coverage of all sciences.  Will cover some journals missed by PubMed and Embase. Some meeting information. No controlled vocabulary.
    Registers trials that are recruting and reports which have been completed.  It also has results for many studies.  Since a majority of the trials in this registry are never published, you'll need to search here if you're looking or clinical trial data.

Databases You Might Search

These database can be an effective complement to your search.  They can be essential in their specialized topic areas.

  • BIOSIS Previews
    Although it is primarly useful for biologists, it contains a lot of meetings and some medical journals.  Controlled vocabulary is not suitable for medical searching.
    Nursing and other health related information; excellent source for issues in patient care.  Well developed controlled vocabulary.
  • PsycINFO
    Cognitive and behavioral therapies are well covered.  Controlled vocabulary.
  • Google Scholar
    Add as an additional source. Here are some search tips.
  • WHO Global Index Medicus
    Search all WHO regional indexes, including the South-East Asia and Western Pacific Pacific regional databases.
  • Sociological Abstracts
    The primary index for sociological literature.  May be useful for community-related studies or interpersonal issues. Controlled vocabulary.
  • 3ie Impact Evaluation Repository
    Investigating an ecomomic or social intervention? The 3ie Impact Evaluation Repository is a currated database for evidence of what works in international development in low- and middle-income countries.
  • EconLit
    Economics. Almost any social intervetion and many medical ones get studied by economists.
    A repository of economics literature. It includes bibliographic metadata from many archives.

Resources for Meetings and Other Grey Literature

Truely unbiased searches look for unpublished literature in a number of places, included meeting abstracts, white papers, clinical trial registries, and searching by hand.

  • OpenGrey
    A multidisciplinary database of technical reports, meetings, dissertations, and official publications. Largely European in focus, it includes records from biomedicine and other sciences, economics, and the humanities.
  • GreyNet
    GreyNet is an organization dedicated to promoting and facilitating the use of grey literature. Includes of listing of grey literature resources, GreySource.
  • Grey Literature Report
    A bi-monthly publication of the New York Academy of Medicine, the GLR includes listings of recently published reports in health science and public health. The archives are tagged with MeSH terms and are searchable.
  • BIOSIS Previews
    Meetings! BIOSIS Previews includes proceedings of many meetings that may not be electronically available elsewhere.

Identifying sources for grey literature and being sure you've done enough is a challenge. The Canadian Agency for Drugs and Technologies in Health (CADTH) feels your pain and has produced a checklist that might help guide your grey research. The Grey Matters checklist provides an organized source of health technology assessment sites, regulatory agencies, trial registries, and other databases in a form that can help ensure the completeness of you search.

Clinical Trial Registries

More information about trial registries and solving the problems associated with searching them is available through this site:
Medical and health-related trials registers and research registers
which is maintained by Julie Glanville and Carol Lefebvre and hosted by the York Health Economics Health Consortium.

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