Evidence-based practice: extending the search to find material for the systematic review

Area of Science:

• Information Science
• Medical Librarianship
• Evidence-Based Practice

Background:

• Systematic reviews increasingly rely on librarian expertise.
• Existing guidelines for systematic review search strategies lack robust evidence.
• This study addresses the evidence gap for recommended search methods.

Purpose of the Study:

• To evaluate the effectiveness of extended systematic search methods for identifying randomized controlled trials (RCTs).
• To quantify the proportion of relevant materials retrieved by different search techniques.
• To compare the yield of specialized databases, hand searching, reference scanning, and personal communication.

Main Methods:

• Prospective monitoring of two systematic review projects.
• Systematic tracking of search methods and retrieved items.
• Calculation of the proportion of RCTs identified by each search strategy.

Main Results:

• Extended systematic search methods identified 29.2% of all retrieved items.
• Specialized database searching was the most effective method.
• Reference list scanning, personal communication, and hand searching followed in effectiveness, with hand searching yielding unique, otherwise missed, items.

Conclusions:

• Extended systematic search methods are valuable for literature retrieval in systematic reviews.
• The effectiveness of these methods is demonstrated by their ability to uncover relevant RCTs.
• Future research should assess the quality of retrieved items to fully evaluate search method value.