title: The natural history of emergent osteoarthritis of the knee in women.
abstract: OBJECTIVE
  We assessed the probability that mid-aged women with a Kellgren and Lawrence (K-L) score of 1 are likely to progress to a score of 2 or regress to a score of zero at a second time point, 2-3 years later.
  
  
  METHODS
  Osteoarthritis (OA) of measurements (weight-bearing X-rays and interviews) were undertaken in women from the Southeast Michigan population who were > or =40 years of age, and who participated in both the 1995 and 1998 measurements (N=679).
  
  
  RESULTS
  Of the 17.1 % of women with a 1995 K-L score of 1 in their right knee, 37.1% had a K-L score of 1 in 1998 while 32.8 % had a score of > or =2 and 30.2% had a score of zero. For 26.0% of women, the score progressed by at least one unit over the 2.5 year period whereas scores for only 7.0% of women regressed in the same time period. Women who had a K-L score of 1 in the right knee in 1995 were 2.5 times more likely to have a K-L score of 1 in 1998 (95% CI=1.6-3.8); and were 2.2 times more likely to have a K-L score of 2 or greater (95% CI=1.4-3.5) in 1998 compared with other scores. These women were 74% less likely to have a score of zero in 1998 (95% CI=0.2-0.4). Further, other risk factors, specifically age and BMI were predictors of increasing K-L grade in 1998.
  
  
  CONCLUSIONS
  These findings suggest that a score of 1 is part of the advancement to emergent OAK; and suggest the following criteria to characterize individuals who are at an intervenable stage on the pathway toward OAK: age > or =40, BMI > or =30, and K-L score of > or =1. From the perspective of both the individual and the examiner, these assessment characteristics are relatively simple to assess clinically.
authors.affiliation: School of Public Health, University of Michigan, Ann Arbor 48109, USA.
authors.forename: L
authors.initials: L
authors.lastname: Lachance
authors.forename: M F
authors.initials: MF
authors.lastname: Sowers
authors.forename: D
authors.initials: D
authors.lastname: Jamadar
authors.forename: M
authors.initials: M
authors.lastname: Hochberg
mesh_terms: D000328:Adult; D018450:Disease Progression; D005260:Female; D006801:Humans; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011336:Probability; D011859:Radiography; D011795:Surveys and Questionnaires