Direct and indirect cost burden associated with multiple sclerosis relapses: Excess costs of persons with MS and their spouse caregivers

Background MS relapses are unpredictable and can be concerning to patients and their caregivers. Objective To assess the direct and indirect cost burden associated with relapses of different severities in MS patients and with MS relapse frequency on spouse caregivers. Methods Using a U.S. insurance claims and employee disability database (1999-2011), we studied adult MS patients (ICD-9-CM: 340.x) and their spouse caregivers. A previously published algorithm to identify relapses was used to stratify: (1) MS patients into cohorts of no, low/moderate, and high severity relapse based on the most severe relapse within one year of follow-up (if any); (2) caregivers into cohorts of no, less, and more frequent relapses based on the overall frequency of relapses of their spouse. Adjusted cost differences and 95% confidence intervals evaluating the yearly incremental costs at 12 months of follow-up (MS patients) and overall (caregivers) associated with relapses are reported. Results Among the 9421 MS patients (N: no relapse = 7686; low/moderate severity relapse = 1220; high severity relapse = 515) identified, both relapse cohorts incurred significantly higher annual incremental direct costs than the no relapse cohort (low/moderate severity = $8269 [6565-10,115]; high severity = $24,180 [20,263-28,482]) and indirect costs (low/moderate severity = $1429 [759-2147]; high severity = $2714 [1468-4035]). More frequent relapses versus no relapse also translated into a significantly greater cost burden for caregivers (direct + indirect = $1725 [376-2885]) but less frequent relapses did not. Conclusions Relapse severity was significantly and increasingly associated with greater direct and indirect costs in MS patients. More frequent relapses also translated into a significant cost burden in spouse caregivers.