Increased socioeconomic burden in patients with primary progressive multiple sclerosis: A Danish nationwide population-based study

Background: Primary progressive multiple sclerosis (PPMS) is characterized by development of more chronic neurological manifestations from disease onset compared with relapsing remitting MS (RRMS) and secondary progressive MS (SPMS) but the following socioeconomic consequences have never been described in a nation-wide patient population. Objective: To determine if socioeconomic burden of PPMS is increased compared with RRMS and SPMS. Methods: We included patients from The Danish Multiple Sclerosis Registry diagnosed between 1998 and 2015. Yearly average health costs, public transfers and earned income was calculated from the index diagnosis date, and each year in a five-year period before and after index diagnosis date, for the three patient groups. A regression model estimating the odds ratio (OR) with PPMS as the comparator, was used to analyze the differences between PPMS vs. RRMS and PPMS vs. SPMS controlling for age and sex. Results: In total, 9563 MS patients were identified (1998–2015), with a characteristic distribution between different disease courses: 7012 patients with RRMS (73%), 1099 patients with PPMS (11%) and 1452 patients with SPMS (15%). Total health costs were lower in RRMS vs. PPMS (OR 0.76; 95% CI 0.74–0.78; p<0.0001) but not in SPMS vs. PPMS (OR 1.06; 95% CI 1.03–1.09; p<0.0001). Especially homecare costs were lower in RRMS vs. PPMS (OR 0.17; 95% CI 0.17–0.18; p<0.0001), less pronounced in SPMS vs. PPMS (OR 0.93; 95% CI 0.90–0.97; p = 0.0001). OR for health costs before and after diagnosis was significantly lower in RRMS vs. PPMS regarding most variables, less pronounced in SPMS vs. PPMS. Conclusion: This nation-wide population-based study show that socioeconomic burden is significantly higher in PPMS relative to RRMS, but less pronounced compared with SPMS.