All-cause health care utilization and costs associated with newly diagnosed multiple sclerosis in the United States.

BACKGROUND: Multiple sclerosis (MS) is a costly and crippling neurologic disease. Approximately 250,000 to 400,000 persons in the United States are currently diagnosed with MS. Most individuals experience their first symptoms between the ages of 20 and 40 years; therefore, this disease may have substantial impact over many years of life on health, quality of life, productivity, and employment. Whereas a number of studies have utilized a cross-sectional design to evaluate the costs associated with MS, no study has used a large administrative claims database to analyze the direct costs associated with newly diagnosed MS.

OBJECTIVE: To estimate the additional health care utilization and costs in otherwise healthy patients with newly diagnosed MS.

METHODS: This was a retrospective cohort analysis of the Medstat MarketScan Commercial Claims and Encounters database, which is composed of medical and pharmacy claims for approximately 8 million beneficiaries from 45 U.S. commercial health plans. Cases extracted from the database included adults aged 18 to 64 years with either (a) at least 2 medical claims with a diagnosis of MS (ICD-9-CM code 340) in any diagnosis field on the claim or (b) 1 prescription (medical or pharmacy) claim for injectable MS drug therapy (interferon beta-1a, interferon beta- 1b, glatiramer acetate) for dates of service between January 1, 2004, and December 31, 2006. Natalizumab was not used to identify MS cases, but was used to exclude potential comparison group subjects. The index date for patients with MS was the first qualifying diagnosis or pharmacy claim. Each MS patient was matched to 5 "healthy comparison" cases without MS diagnoses or treatment using the following variables: region, insurance type, gender, relation to employee, age, and enrollment period. Cases with any condition listed in the Charlson Comorbidity Index were excluded from both the MS and "healthy comparison" cohorts. Each "healthy comparison" case was assigned the index date of the matching MS patient. Continuous enrollment 12 months pre- and post-index was required for both the MS and "healthy comparison" groups. Costs broken down by type of utilization were adjusted to 2010 dollars using the appropriate medical component of the Consumer Price Index. Use of services and costs were compared using chi-square, t-tests, parametric and nonparametric tests.

RESULTS: 1,411 MS cases (65.6% female) were matched to 7,055 "healthy comparison" cases (65.6% female). In the analyses of all-cause health care services during the 12-month post-index period, MS patients were significantly more likely to use all categories of health services examined. Compared with the "healthy comparison" group, new MS patients were 3.5 times as likely to be hospitalized (15.2% vs. 4.3% for MS vs. comparison, respectively), twice as likely to have at least 1 emergency room (ER) visit (25.5% vs. 12.2%) and 2.4 times as likely to have at least 1 visit for physical, occupational, or speech therapy (23.7% vs. 9.9%; P < 0.001 for all comparisons). MS patients also had higher mean 12-month costs related to each category of service (inpatient services $4,110 vs. $836; radiology services $1,693 vs. $259; ER $432 vs. $189; office visits $849 vs. $310; therapies $295 vs. $81, respectively; all P values < 0.001). Total mean 12-month all-cause health care costs were significantly higher for MS patients than for the "healthy comparison" group ($18,829 vs. $4,038, respectively, P < 0.001). Claims attributed to MS by diagnosis code in any field on the claim or use of an MS injectable drug accounted for a mean cost of $8,839 (46.9%), and MS injectable drugs accounted for $4,573 (24.3%) of total all-cause health care costs.

CONCLUSIONS: Newly diagnosed MS patients have significantly higher rates of hospitalizations, radiology services, and ER and outpatient visits compared with non-MS "healthy comparison" patients. MS presents a considerable burden to the U.S. health care system within the first year of diagnosis.