OBJECTIVES: To evaluate the effect of comorbidities on healthcare expenditures and perceived physical and mental health status among adults with Multiple Sclerosis (MS) compared to propensity score-matched non-MS controls.

METHODS: A retrospective, cross-sectional, matched cohort study was conducted using the nationally representative Medical Expenditure Panel Survey (2005-2015) data. The base study sample consisted of adults (age ≥ 18 years) who were alive and had positive total healthcare expenditures during the calendar year. Adults with MS were propensity-matched (1:1) to non-MS controls based on age, gender, and race/ethnicity using a greedy matching algorithm (8:1-digit match). Healthcare expenditures consisted of total and subtypes (inpatient, outpatient, emergency room, prescription drugs, home health agency, dental care, and other expenditures) of healthcare expenditures. Health status consisted of perceived physical and mental health status. Comorbidities were identified using ICD-9-CM and Clinical Classification System codes. Ordinary Least Squares regression and multinomial logistic regression were used to analyze the healthcare expenditures and health status variables, respectively.

RESULTS: The final study sample consisted of 541 adults in each MS and non-MS control groups after propensity score matching. Yearly average total expenditures (expressed in 2018 US$) were significantly (p<0.001) higher for adults with MS ($29,396) compared to propensity score-matched non-MS adults ($7,875). After adjusting for potential confounders, individuals with MS had greater total and sub-types of expenditures compared to non-MS controls, and several comorbidities (e.g., depression, hypertension) were significantly associated with increased healthcare expenditures. Individuals with MS were more likely to report good and poor/fair physical and good mental health status (reference group=excellent) compared to propensity score-matched non-MS controls, and several comorbidities (e.g., anxiety, depression, emphysema, hypertension) were significant independent predictors of lower health status.

CONCLUSIONS: Findings from this study indicate substantial economic and health status burden among adults with MS at US national-level that are significantly influenced by comorbidities.