Cost-of-Illness Progression Before and After Diagnosis of Multiple Sclerosis: A Nationwide Register-Based Cohort Study in Sweden of People Newly Diagnosed with Multiple Sclerosis and a Population-Based Matched Reference Group

BACKGROUND: Multiple sclerosis (MS) is a chronic disease associated with increased healthcare utilisation and productivity losses. OBJECTIVE: The objective of this study was to explore the progression of healthcare costs and productivity losses before and after diagnosis of MS in comparison to that of a population-based matched reference group. METHODS: We conducted a nationwide, Swedish register-based cohort study of working-aged people with MS diagnosed in 2010–12 (n = 1988) and population-based matched references without MS (n = 7981). Nine years of observation spanned from 4 years prior (Y(−4)) to 4 years (Y(+4)) after the year of diagnosis (Y(0)). Differences in annual all-cause healthcare costs (inpatient and specialised outpatient healthcare as well as pharmacy-dispensed prescribed drugs) and costs of productivity loss (days with sickness absence and disability pension) were estimated between the people with MS and references using t tests with 95% confidence intervals. The average excess costs of MS were estimated using generalised estimating equation models. RESULTS: People with multiple sclerosis had higher costs before the diagnosis of MS and also thereafter. The mean differences in healthcare costs and productivity losses between the people with MS and matched references in Y(−4) were 216 EUR (95% confidence interval 58–374) and 1540 EUR (95% confidence interval 848–2233), with larger cost excesses observed in later study years. Summarising the 9 study years, people with MS had fivefold higher excess healthcare costs than references, and more than twice as high productivity losses. CONCLUSIONS: Excess healthcare costs and productivity losses occur already before the diagnosis of MS and increase with time. The excess costs findings before diagnosis could suggest that an earlier diagnosis might lead to reduced excess costs of MS over time. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40273-021-01035-4.