Objectives: To characterize the trends in mean costs and the length of stay (LOS) among hospitalized MS patients.
Methods: Using the 2001-2009 Nationwide Inpatient Sample (NIS) data, primary and secondary discharge diagnoses of MS of ages > 18 years were queried. The discharges were based on International Classification of Disease Clinical Modification ninth edition (ICD-9 CM). Comorbidities queried were hypertension, diabetes, obesity, drug abuse, smoking, alcoholism and lipid disorders. Demographics and baseline information (payer and source of admission) is summarized for primary, secondary MS discharges and controls. Continuous variables of age, cost, length of stay and number died are summarized by descriptive statistics (means and standard deviations). Categorical variables of gender, race and region are presented with frequency distributions (N %) for primary, secondary MS discharges and controls. Only primary MS discharges were considered when describing the trends to include hospitalizations specific to MS. Consumer Price Index (CPI) inflation calculator was used to standardize all costs according to 2012 rates.
Results: The mean LOS in days (±SD) per discharge ranged from 4.49 (± 4.00) - 5.10 (± 9.98). LOS tended to decrease over time. The mean costs (SD) per inpatient admission ranged from 6661 (11600) to 8103 (9940) from 2001-2009. The in hospital MS death rates decreased steadily from 0.48% in 2001 to 0.28% in 2009 except 2004 (0.62%). The rate of emergency admissions increased from 2001-2009. During the same period, contributions from Medicare as the primary payer increased while that of private insurance as the primary payer decreased. From 2001-2009, among primary MS discharges the prevalence of diabetes doubled (8.26% - 18.49%), lipid disorders tripled (4.61% - 14.79%), smoking doubled (8.54%- 22.85%), drug abuse doubled (1.49% - 3.90%) and obesity doubled (3.39% - 7.11%).
Conclusions: The costs of inpatient MS care is increasing steadily. The LOS of inpatient MS care and the number of inpatient MS deaths are decreasing suggesting improved efficiency of care. Also, the costs of inpatient stay/day are increasing. The steady increase in prevalence rates of comorbid disorders may contribute to increasing inpatient costs. Increased emergency and urgent care admissions also may contribute to the growing costs. However, our data does not include or allow analysis of MS disease modifying therapy costs.