Multiple Sclerosis Burden of Illness in the Hawaiian Islands: Ethnic Comparison of Hospitalization Cost and Utilization

Background: The effect of ethnicity on MS risk, disease characteristics, and optimal management is of increasing interest. Most MS trials have not explored the heterogeneity of patients affected by MS, with minorities typically underrepresented. In the Hawaiian Island region, data on burden of illness in MS patients are lacking, with regional data last reported over 30 years ago.

Objectives: To examine differences in cost and hospital length of stay (LOS) in patients with MS in Hawaii by race/ethnicity.

Methods: This was a retrospective, observational study using data from the Hawaii Health Information Corporation database, which has patient demographics, inpatient diagnostics, and discharge information from Hawaii’s 23 acute care hospitals. Hospital admissions and emergency room (ER) visits (2009–2015) were analyzed for patients with MS (ICD-9-CM 340) recorded as the primary or secondary diagnosis. Costs were estimated using standard cost-to-charge metrics determined by All Patient Refined–Diagnosis-Related Groups.

Results: Unique hospital discharges for patients with a primary or secondary diagnosis of MS (N=2281) included ER visits (62%) and inpatient admissions (38%). Mean patient age was 49 years (77% female). Patients were 56% white, 12% Japanese, 10% Native Hawaiian, 8% Filipino, 6% other Asian, 3% black, and 5% other race. Japanese and Native Hawaiian patients comprised 15% and 9% of ER visits, respectively. Native Hawaiian and Filipino patients were each 11% of hospital admissions. Filipino patients had the longest hospital LOS (mean 11 days, median 5 days), and Japanese and white patients had the shortest hospital LOS (mean 7 days, median 5 days). Mean inpatient hospitalization cost range was $14,391 (black patients) to $21,655 (Native Hawaiian patients). Median inpatient hospitalization costs ranged from $9,311 (black patients) to $11,302 (other race). Of the subset of discharges with primary diagnosis of MS (n=343; 15%), black patients had the longest LOS (14 days) and the highest cost ($19,266), and Native Hawaiian patients had the shortest LOS (4 days) and the lowest cost ($9,207).

Conclusions: This descriptive study is one of the first on hospitalization cost and LOS in patients with MS in the Hawaiian Islands by race/ethnicity. Wide ranges of cost and LOS by race suggest that an individualized approach to MS treatment on the Hawaiian Islands may be necessary. Future studies are needed to investigate these differences.