title: Osteoarthritis as a public health problem: the impact of developing knee pain on physical function in adults living in the community: (KNEST 3).
abstract: OBJECTIVE
  To determine the effect of newly developed knee pain on general health and physical function of people >or=50 yrs living in the community.
  
  
  METHODS
  Prospective cohort study of 3907 people aged 50+ registered with three general practices in North Staffordshire, in the UK. The main outcome measures were self-reported knee pain; general health and physical function as measured by the Short Form 36 (SF-36).
  
  
  RESULTS
  Of those with no knee pain at baseline, 24% (n = 501) reported it at follow-up. There was a steep decline in physical function in this group (mean fall in SF-36 score at follow-up 10.3 points) compared with the 1558 persons who had no knee pain at baseline or follow-up (mean fall 3.3). Those with knee pain at baseline whose pain had resolved at 3-yr follow-up (n = 409) showed only minor improvements in physical functioning scores at follow-up (mean improvement -1.3).
  
  
  CONCLUSIONS
  The onset of knee pain is associated with a substantial and persistent reduction of physical function in older adults living in the community. Since knee pain is common, and reduced physical function in mid to older ages is a strong predictor of future disability and dependency, effective prevention or early treatment of knee pain at these ages is likely to have a major influence on healthy ageing in the population.
authors.affiliation: Primary Care Musculoskeletal Research Centre, Keele University, Keele, Staffordshire, UK. c.jinks@cphc.keele.ac.uk
authors.forename: C
authors.initials: C
authors.lastname: Jinks
authors.forename: K
authors.initials: K
authors.lastname: Jordan
authors.forename: P
authors.initials: P
authors.lastname: Croft
mesh_terms: D000368:Aged; D018450:Disease Progression; D004739:England / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology* / Q000534:rehabilitation; D010146:Pain / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology* / Q000534:rehabilitation; D010147:Pain Measurement; D011446:Prospective Studies; D011634:Public Health; D012720:Severity of Illness Index