title: Do patients with elderly-onset rheumatoid arthritis have severe functional disability?
abstract: OBJECTIVE
  To identify the clinical features of elderly-onset rheumatoid arthritis (EORA) and their impact on disease outcome.
  
  
  METHODS
  A total of 3169 rheumatoid arthritis (RA) patients were recruited as part of the Korean Observational Study Network for Arthritis, the nationwide cohort of South Korea. Patients were stratified according to age at disease onset: <40 years (younger age-onset RA, n = 1167), between the ages of 40 and 59 (middle-aged-onset RA, n = 1516), and ≥60 years (EORA, n = 486). To evaluate the significance of differences in clinical features among these 3 groups, we performed analysis of variance (anova) and the χ(2) test. We used multivariable logistic regression analysis to examine the association of onset age with functional disability measured with Health Assessment Questionnaire-Disability Index (HAQDI).
  
  
  RESULTS
  EORA patients were associated with high HAQDI (≥1) in bivariable analysis [odds ratio (OR) 1.36, confidence interval (CI) 1.04-1.77]. However, in multivariable analysis, not elderly onset but patients' age, female gender, high disease activity, disease duration over 10 years, and comorbidity with cardiovascular disease were associated with high HAQDI. Only in a predefined subgroup with disease duration <10 years, elderly onset was an independent influencing factor for the functional disability of RA patients (OR 3.04, CI 1.85-5.67: disease duration of <5 years, OR 3.07, CI 1.64-5.74: disease duration of 5 to 10 years).
  
  
  CONCLUSIONS
  Disease onset in older age was associated independently with functional disability of RA patients who have relatively short disease duration.
authors.affiliation: Hanyang University Hospital for Rheumatic Diseases, Seoul, South Korea.
authors.forename: Soo-Kyung
authors.initials: SK
authors.lastname: Cho
authors.forename: Yoon-Kyoung
authors.initials: YK
authors.lastname: Sung
authors.forename: Chan-Bum
authors.initials: CB
authors.lastname: Choi
authors.forename: Hoon-Suk
authors.initials: HS
authors.lastname: Cha
authors.forename: Jung-Yoon
authors.initials: JY
authors.lastname: Choe
authors.forename: Won Tae
authors.initials: WT
authors.lastname: Chung
authors.forename: Seung-Jae
authors.initials: SJ
authors.lastname: Hong
authors.forename: Jae-Bum
authors.initials: JB
authors.lastname: Jun
authors.forename: Jinseok
authors.initials: J
authors.lastname: Kim
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Kim
authors.forename: Tae-Jong
authors.initials: TJ
authors.lastname: Kim
authors.forename: Eun-Mi
authors.initials: EM
authors.lastname: Koh
authors.forename: Hye-Soon
authors.initials: HS
authors.lastname: Lee
authors.forename: Jisoo
authors.initials: J
authors.lastname: Lee
authors.forename: Shin-Seok
authors.initials: SS
authors.lastname: Lee
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Dae-Hyun
authors.initials: DH
authors.lastname: Yoo
authors.forename: Bo Young
authors.initials: BY
authors.lastname: Yoon
authors.forename: Sang-Cheol
authors.initials: SC
authors.lastname: Bae
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D017668:Age of Onset; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D015331:Cohort Studies; D004185:Disability Evaluation; D006233:Persons with Disabilities; D005260:Female; D006304:Health Status; D006801:Humans; D007596:Joints / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D056910:Republic of Korea / Q000453:epidemiology; D011795:Surveys and Questionnaires; D013997:Time Factors