RT Journal Article SR Electronic T1 Age and disability accumulation in multiple sclerosis JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP 1246 OP 1252 DO 10.1212/WNL.0b013e318230a17d VO 77 IS 13 A1 Scalfari, A. A1 Neuhaus, A. A1 Daumer, M. A1 Ebers, G.C. A1 Muraro, P.A. YR 2011 UL http://n.neurology.org/content/77/13/1246.abstract AB Objectives: We tested the hypothesis that age is a prognostic factor with respect to long-term accumulation of disability in multiple sclerosis (MS). Methods: Kaplan-Meier analysis and binary logistic regression models determined the effect of age at disease onset, age at onset of progression, and current age on attainment of severe disability levels (Disability Status Scale [DSS] 6–8–10) from the London, Ontario, database (n = 1,023). Results: Older age at relapsing-remitting (RR) phase onset was associated with higher risk of reaching advanced DSS scores. This was independent of disease duration and early relapse frequency but secondary to increased risk of conversion to secondary progressive (SP) MS. Onset at age 40 (odds ratio [OR] = 4.22) and at age 50 (OR = 6.04) doubled and tripled risks of developing SP, compared to age 20 (OR = 2.05). Younger age at conversion to SPMS was associated with shorter times to high DSS scores from disease onset. The progressive course, unaffected by age at RR onset, was only modestly affected by age at SP onset. Among primary progressive and RR/SP patients, median ages at attainment of DSS scores were strikingly similar: DSS = 6, 49 vs 48 years; DSS = 8, 58 vs 58 years; and DSS = 10, 78 years for both (p = NS for all comparisons). Conclusions: Development of SP is the dominant determinant of long-term prognosis, independent of disease duration and early relapse frequency. Age independently affects disability development primarily by changing probability and latency of SP onset, with little effect on the progressive course. CI=confidence interval; DMT=disease-modifying therapy; DSS=Disability Status Scale; MC=Middlesex County; MS=multiple sclerosis; OR=odds ratio; PP=primary progressive; PR=progressive relapsing; RR=relapsing-remitting; SO=patients seen from disease onset; SP=secondary progressive