title: The influence of age at disease onset on disease activity and disability: results from the Ontario Best Practices Research Initiative.
abstract: This study aims to compare characteristics between late-onset rheumatoid arthritis (RA) and young-onset RA and determine the association between age at disease onset and disease severity. We cross-sectionally studied 971 patients at the time of entry into the Ontario Best Practices Research Initiative, a registry of RA patients followed up in routine care. We restricted patients to ≤5 years of disease duration. Late-onset RA was defined as an onset ≥60 years of age and young-onset RA <60 years. Group differences were compared, and multivariate linear regression models were used to test the influence of age at onset on Disease Activity Score in 28 Joints with erythrocyte sedimentation rate (DAS28-ESR), Clinical Disease Activity Index (CDAI), and Health Assessment Questionnaire (HAQ) scores. The swollen joint count (6.2 vs. 5.3), acute phase reactants (C-reactive protein (CRP) 17.4 vs. 11.8 mg/L, ESR 30.6 vs. 21.5 mm/h), and comorbidity burden were higher in late-onset RA compared to young-onset RA (p < 0.01). Mean DAS28-ESR (4.6 vs. 4.3) and HAQ (1.2 vs. 1.1) scores were higher in late-onset RA patients (p < 0.05). Late-onset RA patients received more initial disease-modifying antirheumatic drug (DMARD) monotherapy and corticosteroids in comparison to greater DMARD/biologic combination therapy in young-onset RA patients (p < 0.05). Adjusted multivariate analyses showed that late-onset RA was independently associated with higher mean DAS28-ESR and HAQ scores, but not CDAI. Late-onset RA patients have greater disease activity that may contribute to disability early in the disease course. Despite this, initial treatment consists of less combination DMARD and biologic use in late-onset RA patients. This may have implications for future response to therapy and development of joint damage, disability, and comorbidities in this group.
authors.affiliation: Rheumatology Division, University of Toronto, Sunnybrook Hospital, 2075 Bayview Avenue, Suite M1-400, Toronto, ON, M4N 3M5, Canada. thanu.ruban1@gmail.com.
authors.forename: T N
authors.initials: TN
authors.lastname: Ruban
authors.affiliation: University of Toronto, 200 Elizabeth Street, 13EN-22, Toronto, ON, M5G 2C4, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Jacob
authors.affiliation: Division of Rheumatology, Department of Medicine, Western University, St. Joseph's Health Care, 268 Grosvenor Street, London, ON, N6A 4V2, Canada.
authors.forename: J E
authors.initials: JE
authors.lastname: Pope
authors.affiliation: The Rebecca MacDonald Centre for Arthritis and Autoimmune Disease, Mount Sinai Hospital, Room 2-006 Box 4, 60 Murray Street, Toronto, ON, M5T 3L9, Canada.
authors.forename: E C
authors.initials: EC
authors.lastname: Keystone
authors.affiliation: University of Toronto, Canada, Suite 2-008 Box 7, 60 Murray Street, Toronto, ON, M5T 3L9, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Bombardier
authors.affiliation: The Rebecca MacDonald Centre for Arthritis and Autoimmune Disease, Mount Sinai Hospital, University of Toronto, 2nd Floor, Room 2-008, 60 Murray Street, Toronto, ON, M5T 3L9, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Kuriya
mesh_terms: D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000188:drug therapy; D004185:Disability Evaluation; D006233:Persons with Disabilities; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009864:Ontario; D012042:Registries; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
chemical_list: D018501:Antirheumatic Agents
keywords: Age of disease onset; Disease activity; Elderly onset; Rheumatoid arthritis