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Department of Health and Human Services

How Are Evidence-based Practice Center Systematic Reviews Updated?

Many factors influence the decision to update systematic reviews. In the face of limited resources, organizations must prioritize which reports are put under surveillance and subsequently updated when appropriate.

The AHRQ Evidence-based Practice Center (EPC) program has instituted a process to select systematic reviews for update.  The stakeholder impact of each active report is assessed annually, and the reports are categorized as high, moderate, or low stakeholder impact (see diagram). The stakeholder impact is determined by the utility and uptake of the report. This is measured by frequency of download of the report or related products, interest from stakeholder partners, and citation in other scientific literature, including clinical practice guidelines.

For reports with the highest stakeholder impact, the AHRQ EPC program commits resources to annual updates of these reports. These reports do not undergo currency surveillance, as described below.

For reports of moderate stakeholder impact, the AHRQ EPC program conducts annual currency surveillance. Methods for surveillance of the currency of systematic reviews have been previously published1,2,3,4.  For currency surveillance, the Scientific Resource Center gathers data on whether new research is available and whether the report’s conclusions are considered outdated. The AHRQ EPC program then evaluates reports identified as out of date in its established process for topic selection. (See diagram at:

Reports in the lowest tier of stakeholder impact are assessed annually for stakeholder impact for three years, and may be moved to a higher tier based on this assessment. These reports do not undergo currency surveillance. Reports that remain in the lowest tier for 3 years are archived.

This newly developed process will be reviewed and revised on an ongoing basis.

This figure illustrates the AHRQ EPC program process for identifying reports for update. Proceeding from left to right, all EPC reports undergo stakeholder impact assessment, and are classified as high impact, moderate impact and low impact. All high impact reports proceed with scheduled update. Moderate impact reports undergo currency surveillance, and are classified as up to date or out of date. Moderate impact out of date reports, undergo a topic selection process. After this process they either undergo update, repeated stakeholder impact assessment or are archived. Low impact reports are categorized as either less than three years old or greater than three years old. Those less than three years old undergo stakeholder impact assessment annually. Those greater than three years old are archived.


  1. Tsertsvadze A, Maglione M, Chou, R, Garritty C, Coleman C, Lux L, Bass E, Balshem H, Moher D. Updating Comparative Effectiveness Reviews: Current Efforts in AHRQ’s Effective Health Care Program. Methods Guide for Comparative Effectiveness Reviews. (Prepared by the University of Ottawa EPC, RAND Corporation–Southern California EPC, Oregon EPC, University of Connecticut EPC, RTI–University of North Carolina EPC, Johns Hopkins Bloomberg School of Public Health EPC under Contract No. 290-02-0021 EPC2). AHRQ Publication No. 11-EHC057-EF. Rockville, MD: Agency for Healthcare Research and Quality. July 2011. Available at:
  2. Shekelle PG, Newberry SJ, Wu H, Suttorp M, Motala A, Lim Y-W, Balk EM, Chung M, Yu WW, Lee J, Gaylor JM, Moher D, Ansari MT, Skidmore R, Garritty C. Identifying Signals for Updating Systematic Reviews: A Comparison of Two Methods. Rockville (MD): Agency for Healthcare Research and Quality. June 2011. Methods Research Report. AHRQ Publication No. 11-EHC042-EF. Available at:
  3. Newberry SJ, Ahmadzai N, Motala A, Tsertsvadze A, Maglione M, Ansari MT, Hempel S, Tsouros S, Schneider Chafen J, Shanman R, Skidmore B, Moher D, Shekelle PG. Surveillance and Identification of Signals for Updating Systematic Review: Implementation and Early Experience. Methods Research Report (Prepared by the RAND Corporation, Southern California Evidence-based Practice Center under Contract No. 290-2007-10062-I and University of Ottawa Evidence-based Practice Center 290-2007-10059-I). AHRQ Publication No. 13-EHC088-EF. Rockville, MD: Agency for Healthcare Research and Quality; June 2013. Available at:
  4. Shekelle PG, Motala A, Johnsen B. Assessment of a Method To Detect Signals for Updating Systematic Reviews. Research White Paper (Prepared by the Southern California Evidence-based Practice Center under Contract No. 290-2007-10062-I). AHRQ Publication No. 14-EHC015. Rockville, MD: Agency for Healthcare Research and Quality. March 2014. Available at: