title: Median life span of a cohort of National Institute for Health and Care Excellence clinical guidelines was about 60 months.
abstract: OBJECTIVE
  To describe the length of time National Institute for Health and Care Excellence (NICE) clinical guidelines have remained valid.
  
  
  METHODS
  The present study is a survival analysis of a cohort of published NICE clinical guidelines. The National Health Service in England and Wales uses NICE clinical practice guidelines as a reference for treatment and care of individuals. They need to be updated as new evidence arises, to remain credible and relevant, and are currently assessed 3 years after publication.
  
  
  RESULTS
  Survival analysis suggested that about 86% of guidelines are still up-to-date 3 years after their publication. The median life span was 60 months (95% confidence interval: 51, 69).
  
  
  CONCLUSIONS
  These findings are similar to those in other studies of the life span of guidelines. Efficient mechanisms must be in place to detect the minority of guidelines that become outdated quickly.
authors.affiliation: Centre for Clinical Practice, National Institute for Health and Care Excellence, Level 1A, City Tower, Piccadilly Plaza, Manchester M1 4BD, United Kingdom.
authors.forename: Lucy J H
authors.initials: LJ
authors.lastname: Alderson
authors.forename: Phil
authors.initials: P
authors.lastname: Alderson
authors.forename: Toni
authors.initials: T
authors.lastname: Tan
mesh_terms: D015331:Cohort Studies; D004739:England; D006077:Government Agencies / Q000458:organization & administration*; D006801:Humans; D020380:Needs Assessment; D016134:Organizational Policy; D017410:Practice Guidelines as Topic; D016019:Survival Analysis; D013997:Time Factors; D014852:Wales
keywords: Clinical guidelines; NICE; best practice; life span; survival analysis; updating