title: Descriptive epidemiology of osteoarthritis in British Columbia, Canada.
abstract: OBJECTIVE
  Osteoarthritis (OA) is a highly prevalent and often disabling disease. Data on the incidence of OA in the general population are limited. Our objectives were (1) to estimate OA prevalence and incidence rates by age and sex in a geographically defined population of 4 million people [British Columbia (BC), Canada] using an administrative database; and (2) to determine the effects of different administrative definitions of OA and observation (run-in) time on such estimates.
  
  
  METHODS
  We used data on all visits to health professionals and hospital admissions covered by the Medical Services Plan (MSP) of BC for the fiscal years 1991-92 through 2000-01. OA was defined based on International Classification of Diseases, 9th Revision, diagnostic codes required for administrative purposes.
  
  
  RESULTS
  The overall prevalence of OA in 2001 was 10.8%: 8.9% in men and 12.6% in women. Prevalence was higher in women in all age groups. By age 70-74 years, about one-third of men and 40% of women had OA. Incidence rates in 2000-01 were 11.7 per 1000 person-years in the total population, 10.0 in men and 13.4 in women. Rates increased linearly with age between 50 and 80 years. Both prevalence and incidence depended strongly on the definition of OA and the run-in period.
  
  
  CONCLUSIONS
  Prevalence of physician-diagnosed OA in BC was slightly lower than self-reported prevalence of arthritis in population surveys. Routinely collected administrative data could be a valuable source of information for OA surveillance, but more research is needed on the validity of OA diagnosis in administrative databases.
authors.affiliation: Department of Health Care and Epidemiology, University of British Columbia, Vancouver, BC, Canada. jkopec@arthritisresearch.ca
authors.forename: Jacek A
authors.initials: JA
authors.lastname: Kopec
authors.forename: M Mushfiqur
authors.initials: MM
authors.lastname: Rahman
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Berthelot
authors.forename: Christel
authors.initials: C
authors.lastname: Le Petit
authors.forename: Jaafar
authors.initials: J
authors.lastname: Aghajanian
authors.forename: Eric C
authors.initials: EC
authors.lastname: Sayre
authors.forename: Jolanda
authors.initials: J
authors.lastname: Cibere
authors.forename: Aslam H
authors.initials: AH
authors.lastname: Anis
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Badley
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001955:British Columbia / Q000453:epidemiology; D002648:Child; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D012680:Sensitivity and Specificity; D017678:Sex Distribution