Rates of Comorbidities in Patients with and without Multiple Sclerosis: A US Retrospective Claims Database Analysis

Background: Few published studies have assessed the prevalence of comorbidities in patients with multiple sclerosis (MS) in the US. 

Objectives: To compare the prevalence of comorbidities in patients with and without MS using a large US administrative claims database.

Methods: This study used IMS Health Real World Data Adjudicated Claims – US data from January 1, 2011 to September 30, 2015. Patients with MS were required to have a minimum of two claims with a diagnosis of MS 30 days apart (ICD-9-CM code 340.xx), and were aged 18–65 years. Charlson Comorbidity Index comorbidities and ten of the most common comorbidities in MS were compared. Exact matching was used to match patients with MS 1:1 to the pool of patients without MS. Matching factors included age group (5-year intervals), sex, region, and index-year quarter.

Results: Patients with MS (n=69,550) were matched to the pool of patients without MS (n=3,129,573) to get a final sample of 66,616 for each arm. Mean (standard deviation [SD]) age was 45.63 (10.43) years with MS and 45.59 (10.50) years without MS, and 76.24% were female (both groups). Most patients were from the Midwest (32.68% both groups), South (30.47% both groups), or Northeast (27.59% both groups), and had commercial insurance (>95% for both). The most common comorbidities were hyperlipidemia (27.76% with vs. 24.57% without MS), hypertension (26.91% with vs. 23.50% without MS), gastrointestinal disorders (18.02% with vs. 13.84% without MS), depression (16.12% with vs. 9.62% without MS), thyroid disease (15.77% with vs. 12.05% without MS), anxiety (12.27% with vs. 9.32% without MS), and chronic pulmonary disease (10.39% with vs. 9.52% without MS) (all p<0.0001). More patients with MS had arthritis, prior malignancy, cerebrovascular disease, congestive heart failure, dementia, diabetes with complications, hemiplegia or paraplegia, myocardial infarction, peptic ulcer disease, peripheral vascular disease, and renal disease (p<0.05). More patients without MS had AIDS, alcohol abuse, mild liver disease, and moderate/severe liver disease (p<0.05). There were no differences in the prevalence of diabetes without complications or metastatic solid tumor (p>0.05).

Conclusions: Hyperlipidemia, hypertension, gastrointestinal disorders, depression, thyroid disease, anxiety, and chronic pulmonary disease were common in patients with MS. Many comorbidities occurred in statistically significantly greater frequency in patients with MS.