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Systematic Reviews: Searching

A guide to conducting systematic reviews.

Searching Manuals and Checklists



Librarians Can Help!

Reference librarians trained in the systematic review process are available to assist with planning and conducting a review. Email the Reference Department or phone 718-430-3104 to set up an appointment.

The Institute of Medicine Standards for Systematic Reviews include the following requirement (Standard 3.1.1):

"Work with a librarian or other information specialist trained in performing systematic reviews to plan the search strategy"

The Methods Guide for Effectiveness and Comparative Effectiveness Reviews from the Agency for Healthcare Research and Quality (AHRQ) recommends that “[a] librarian or other expert searcher should be involved in the development of the search.”

Developing the Search Strategy

A systematic review aims to include all relevant studies. Increasing the comprehensiveness (or sensitivity) of a search will reduce its precision and will retrieve more irrelevant articles. Recall (sensitivity) is defined as the number of relevant reports identified divided by the total number of relevant reports in existence. Precision (specificity) is defined as the number of relevant reports identified divided by the total number of reports identified. A thorough search takes time to develop and perform. Issues to consider in performing a comprehensive search:

  • Inclusion of all concepts in the strategy
  • Use of all appropriate subject headings
  • Appropriate "exploding" of subject headings
  • Appropriate use of subheadings
  • Use of natural language (text words) in addition to controlled vocabulary terms
  • Use of appropriate synonyms, acronyms, etc.
  • Truncation and spelling variation as appropriate
  • Appropriate use of limits, such as language, years, etc.
  • Field searching, publication type, author, etc.
  • Appropropriate use of Boolean operators
  • Double-checking the correct combining of line numbers to eliminate "line errors"
  • Adaptation of the search strategy for multiple databases