Validity of the agency for healthcare research and quality clinical practice guidelines - How quickly do guidelines become outdated?

Context Practice guidelines need to be up-to-date to be useful to clinician s. No published methods are available for assessing whether existing practi ce guidelines are still valid, nor does any empirical information exist reg arding how often such assessments need to be made. Objectives To assess the current validity of 17 clinical practice guideline s published by the US Agency for Healthcare Research and Quality (AHRQ) tha t are still in circulation, and to use this information to estimate how qui ckly guidelines become obsolete. Design, Setting, and Participants We developed criteria for defining when a guideline needs updating, mailed surveys to members of the original AHRQ g uideline panels (n = 170; response rate, 71%), and searched the literature for evidence through March 2000 (n = 6994 titles yielding 173 articles plus 159 new guidelines on the same topics). Main Outcome Measures Identification of new evidence calling for a major, m inor, or no update of the 17 guidelines; survival analysis of the rate at w hich guidelines became outdated. Results For 7 guidelines, new evidence and expert judgment indicated that a major update is required; 6 were found to be in need of a minor update; 3 were judged as still valid; and for 1 guideline, we could reach no conclusi on. Survival analysis indicated that about half the guidelines were outdate d in 5.8 years (95% confidence interval [CI], 5.0-6.6 years). The point at which no more than 90% of the guidelines were still valid was 3.6 years (95 % CI, 2.6-4.6 years). Conclusions More than three quarters of the AHRQ guidelines need updating. As a general rule, guidelines should be reassessed for validity every 3 yea rs.