title: Hip osteoarthritis prevalence estimates by three radiographic scoring systems.
abstract: OBJECTIVE
  To estimate and compare the age- and sex-specific prevalence of radiographic hip osteoarthritis (RHOA) in a population-based study of the Pima Indians, using 3 atlas-based methods for assessing features of RHOA.
  
  
  METHODS
  Pelvic radiographs from 755 Pima Indians age > or = 45 years enrolled in a population-based study were read using the Kellgren/Lawrence (K/L) grading scale (grade 0-4) and 2 validated individual-radiographic-features (IRF) scales (grades 0-3 for narrowing and osteophytes).
  
  
  RESULTS
  The age- and sex-specific prevalence of RHOA among Pima Indians assessed using the K/L scale was < 10% in all age and sex groups. The prevalence of grade > or = 2 osteophytes assessed using the 2 IRF scales were similar to each other in all age and sex groups. However, differences between the 2 IRF scoring systems were found for the prevalence of grade > or = 2 joint space narrowing.
  
  
  CONCLUSIONS
  Pima Indians have an age- and sex-specific prevalence of RHOA similar to that found in the US population. Our finding of different joint space narrowing prevalence by the 2 IRF grading scales supports the use of the same atlas-based case definitions for determining disease prevalence for comparative studies.
authors.affiliation: National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, Maryland 20892-3675, USA.
authors.forename: R
authors.initials: R
authors.lastname: Hirsch
authors.forename: R J
authors.initials: RJ
authors.lastname: Fernandes
authors.forename: S R
authors.initials: SR
authors.lastname: Pillemer
authors.forename: M C
authors.initials: MC
authors.lastname: Hochberg
authors.forename: N E
authors.initials: NE
authors.lastname: Lane
authors.forename: R D
authors.initials: RD
authors.lastname: Altman
authors.forename: D A
authors.initials: DA
authors.lastname: Bloch
authors.forename: W C
authors.initials: WC
authors.lastname: Knowler
authors.forename: P H
authors.initials: PH
authors.lastname: Bennett
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001175:Arthrography / Q000379:methods*; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006801:Humans; D007198:Indians, North American; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D010003:Osteoarthritis / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D010388:Pelvis / Q000000981:diagnostic imaging; D015995:Prevalence; D017678:Sex Distribution