title: Assessing the need to update prevention guidelines: a comparison of two methods.
abstract: BACKGROUND
  An important concern for developers of clinical practice guidelines is how best to determine when guidelines require updating to ensure they remain current and evidence based. Because of the high costs associated with updating guidelines, recent attention has focused on approaches that can reliably assess the extent of updating required. Recently, Shekelle and colleagues proposed a model of limited literature searches with modest expert involvement as a way to reduce the cost and time requirements for assessing whether a guideline needs updating.
  
  
  METHODS
  The main objective of this study was to compare the Shekelle et al. assessment model (review approach) and a conventional process using typical systematic review methods (traditional approach) in terms of comprehensiveness and effort. We modeled the review approach on that by Shekelle and colleagues but refined it iteratively over three phases to achieve greater efficiency. Using both methods independently, we assessed the need to update six topics from the 1996 Guide to Clinical Preventive Services from the US Preventive Services Task Force. Main outcomes included completeness of study identification, importance of missed studies and the effort involved.
  
  
  RESULTS
  Although the review approach identified fewer eligible studies than the traditional approach, none of the studies missed was rated as important by task force members acting as liaisons to the project with respect to whether the topic required an update. On average, the review approach produced substantially fewer citations to review than the traditional approach. The effort involved and potential time saving depended largely on the scope of the topic.
  
  
  CONCLUSIONS
  The revised review approach provides an efficient and acceptable method for judging whether a guideline requires updating.
authors.affiliation: Cecil G. Sheps Center for Health Services Research, University of North Carolina, 725 Airport Road, Chapel Hill, NC 27599-7590, USA. gartlehner@schsr.unc.edu
authors.forename: Gerald
authors.initials: G
authors.lastname: Gartlehner
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: West
authors.forename: Kathleen N
authors.initials: KN
authors.lastname: Lohr
authors.forename: Leila
authors.initials: L
authors.lastname: Kahwati
authors.forename: Jana G
authors.initials: JG
authors.lastname: Johnson
authors.forename: Russell P
authors.initials: RP
authors.lastname: Harris
authors.forename: Lynn
authors.initials: L
authors.lastname: Whitener
authors.forename: Christiane E
authors.initials: CE
authors.lastname: Voisin
authors.forename: Sonya
authors.initials: S
authors.lastname: Sutton
mesh_terms: D001437:Bacteriuria / Q000517:prevention & control; D019317:Evidence-Based Medicine; D005901:Glaucoma / Q000517:prevention & control; D006453:Hemoglobinopathies / Q000517:prevention & control; D006561:Herpes Simplex / Q000517:prevention & control; D006801:Humans; D016247:Information Storage and Retrieval / Q000379:methods; D008403:Mass Screening / Q000592:standards; D017410:Practice Guidelines as Topic; D011315:Preventive Medicine / Q000592:standards*; D011785:Quality Assurance, Health Care / Q000379:methods*; D013587:Syphilis / Q000517:prevention & control; D001749:Urinary Bladder Neoplasms / Q000517:prevention & control