title: The impact of non-traumatic hip and knee disorders on health-related quality of life as measured with the SF-36 or SF-12. A systematic review.
abstract: OBJECTIVE
  The purpose of this review is to summarize the available evidence on the impact of non-traumatic hip or knee disorders on health-related quality of life (HRQL), as measured with the Short Form 36 Health Survey (SF-36) or Short Form 12 Health Survey (SF-12), by comparing this with data from reference populations.
  
  
  METHODS
  Studies were identified by an electronic search of the MEDLINE, PsychInfo and Cinahl databases. Studies with the following features were included: study population included patients with non-traumatic hip or knee disorders, the SF-36 or SF-12 was used as an outcome measure and mean scores on these HRQL measures were presented. Using mean HRQL scores from the selected studies and scores from reference populations, z-scores were computed. Pooled estimates were computed for subgroups of studies with similar patients in similar settings.
  
  
  RESULTS
  A total of 40 studies met the inclusion criteria. Patients with non-traumatic hip and knee disorders scored up to 2.5 standard deviations (SDs) below reference population values, especially on the physical aspects of HRQL. Social and mental aspects were up to 1 SD below reference population values, especially in patients in clinical settings.
  
  
  CONCLUSIONS
  The impact of non-traumatic hip or knee disorders on HRQL is substantial, especially on the physical aspects of HRQL.
authors.affiliation: Institute for Research in Extramural Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Johanna M
authors.initials: JM
authors.lastname: van der Waal
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Terwee
authors.forename: Daniëlle A W M
authors.initials: DA
authors.lastname: van der Windt
authors.forename: Lex M
authors.initials: LM
authors.lastname: Bouter
authors.forename: Joost
authors.initials: J
authors.lastname: Dekker
mesh_terms: D006304:Health Status; D006801:Humans; D009140:Musculoskeletal Diseases / Q000503:physiopathology*; D015207:Osteoarthritis, Hip / Q000503:physiopathology* / Q000601:surgery; D020370:Osteoarthritis, Knee / Q000503:physiopathology* / Q000601:surgery; D011788:Quality of Life; D018434:Sickness Impact Profile