title: Effect of ethnicity on disease activity and physical function in psoriatic arthritis in a multiethnic Asian population.
abstract: Geographic differences in manifestation of psoriatic arthritis (PsA) could be related to differences in genetic or environmental factors. We aimed to compare the disease activity and functional status using validated outcome measures among patients with PsA of different ethnicities living in the same environment. We performed a cross-sectional study on consecutive patients with PsA classified by the Classification Criteria for Psoriatic Arthritis (CASPAR) criteria from a single center. Sociodemographic data, clinical variables, and patient-reported outcomes were collected using a standardized protocol. Disease activities were assessed by validated composite scores: clinical Disease Activity Index for Psoriatic Arthritis (cDAPSA), Composite Psoriatic Disease Activity Index (CPDAI), and minimal disease activity (MDA). Physical function was assessed with Health Assessment Questionnaire (HAQ) and the Medical Outcome Study Short-Form 36 (SF36) physical function subscales. Linear regression analyses were performed to identify variables associated with disease activities and physical function. Ninety-eight patients (51.5%, men) with mean (±SD) age and duration of PsA of 51.5 ± 13.8 and 5.5 ± 8.4 years were recruited. Indian was overrepresented compared with the national distribution of ethnicities. Compared to Chinese, Indian patients were more likely to be using biological therapies, have higher tender joint count, and worse enthesitis. Higher proportion of Indians had higher disease activity categories measured by cDAPSA, CPDAI, and MDA and had poorer physical function. In the multivariable analysis, ethnicity was significantly associated with HAQ and SF36-PF. Compared to Chinese, Indians with PsA living in the same environment had worse disease activity and physical function measured by validated outcomes.
authors: Department of Rheumatology and Immunology, Singapore General Hospital, The Academia, level 4, 20 College Road, Singapore, 169856, Singapore. katyccc@hotmail.com.|Duke-NUS Medical School, Singapore, Singapore. katyccc@hotmail.com.
authors: Ying Ying
authors: YY
authors: Leung
authors: Department of Rheumatology and Immunology, Singapore General Hospital, The Academia, level 4, 20 College Road, Singapore, 169856, Singapore.|Duke-NUS Medical School, Singapore, Singapore.
authors: Warren
authors: W
authors: Fong
authors: Department of Rheumatology and Immunology, Singapore General Hospital, The Academia, level 4, 20 College Road, Singapore, 169856, Singapore.
authors: Nai Lee
authors: NL
authors: Lui
authors: Department of Rheumatology and Immunology, Singapore General Hospital, The Academia, level 4, 20 College Road, Singapore, 169856, Singapore.|Duke-NUS Medical School, Singapore, Singapore.
authors: Julian
authors: J
authors: Thumboo
mesh_terms: D000328:Adult; D000368:Aged; D015535:Arthritis, Psoriatic / Q000175:diagnosis / Q000208:ethnology* / Q000503:physiopathology*; D044466:Asian People / Q000208:ethnology*; D002681:China; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005843:Geography; D006801:Humans; D007194:India; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012074:Remission Induction; D012720:Severity of Illness Index; D012846:Singapore / Q000453:epidemiology; D011795:Surveys and Questionnaires
keywords: Disease activity; Ethnicity; Patient-reported outcomes; Physical function; Psoriatic arthritis