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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

Title: The title of the image is “Review Process Schedule.”
Timeline and Bars: The image depicts a timeline or schedule horizontally. It consists of several yellow bars, each representing a different stage or task in the review process. These bars extend over specific months.
Stages and Estimated Timeframes:
Preparation of Protocol: This stage spans from month 1 to month 2.
Searches for Published and Unpublished Studies: This stage occurs between months 3 and 8.
Pilot Test of Eligibility Studies: The pilot test happens during months 2 and 3.
Inclusion Assessments: This stage covers months 3 to 8.
Pilot Test of Risk Bias Assessment: The pilot test for risk bias assessment occurs in month 3.
Validity Assessments: Validity assessments take place from month 3 to month 10.
Pilot Test of Data Collection: The pilot test for data collection happens in month 3.
Data Collection: Data collection spans from month 3 to month 10.
Data Entry: Data entry occurs during months 3 to 10.
Follow-Up on Missing Information: This task happens between months 5 and 11.
Analysis: The analysis stage takes place from month 8 to month 10.
Preparation of Review Report: The review report is prepared in month 11.
Keeping Review Up-to-Date: Starting from month 12 onwards, the review is kept 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