Clinical course of multiple sclerosis and labor-force absenteeism: a longitudinal population-based study.

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is a chronic neurological disease associated with substantial disability and morbidity. The objective of our study was to assess long-term consequences of MS clinical course on sick leave and disability pension.

METHODS: Patients with relapse-remitting MS (RRMS), secondary progressive MS (SPMS), and primary progressive MS (PPMS) were identified through the Swedish Multiple Sclerosis Registry. We calculated the mean annual prevalence and number of sick leave and disability pension days by clinical course, age, and year pre and post diagnosis, and compared outcomes using Welch's t-tests and analysis-of-variance models, mixed-effects regression, and survival analysis.

RESULTS: The sample included 5,371 patients (4,568 with RRMS, 390 with SPMS, and 413 with PPMS). The mean annual number of days with sick leave and disability pension ranged from 101 one year after diagnosis to 164 after 11 years for patients with RRMS. Corresponding estimates for PPMS were 188 and 311 days. Higher levels of absenteeism were observed in patients with PPMS versus RRMS seven years before diagnosis for sick leave (p<0.025) and 10 years for disability pension (p<0.034). Differences between SPMS and PPMS were minor.

CONCLUSIONS: Patients with RRMS have substantially lower levels of sick leave and disability pension over time compared with their counterparts with SPMS and PPMS, while labour-force absenteeism is similar for patients with SPMS and PPMS. These findings contribute to the understanding of the impact of MS on socio-economic outcomes and help inform the discussion on the clinical classification of different courses of the disease. This article is protected by copyright. All rights reserved.