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Systematic Searching Support

Setting Expectations

Most thorough reviews require at least 6 months to complete, and often take 1-2 years. The resources below provide a sense of what to expect for a systematic review. but are applicable to most comprehensive reviews that follow established methodology. 

Timeline for a Systematic Review

Month Activity 1-2 preparation of protocol 3-8 searches for published and unpublished studies 2-3 pilot test of eligibility studies  3-8 inclusion assessments 3 pilot test of risk of bias assessment 3-10 validity assessments 3 pilot test of data collection 3-10 data collection 3-10 data entry 5-11 follow up of missing information 8-10 analysis 1-11 preparation of review report 12- keeping the review up-to-date


Source: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from

Time Requirement Study

A study which measured time requirements for systematic reviews not published with Cochrane found that the average time from start to finish is 1 year. The study below includes analysis of major review tasks. 

Borah R, Brown AW, Capers PL, Kaiser KA. Analysis of the time and workers needed to conduct systematic reviews of medical interventions using data from the PROSPERO registry. BMJ open. 2017;7(2):e012545. View full text