Trends in Outcomes and Hospitalization Charges among Mechanically Ventilated Patients with Myasthenia Gravis in the United States

INTRODUCTION To assess the impact of new therapeutic strategies on outcome and cost of hospitalization among patients with myasthenia gravis (MG) who are mechanically ventilated in United States. METHODS Using a retrospective analysis of cross sectional survey, we determined the rates of occurrence, in-hospital outcomes, and mean hospital charges for patients hospitalized with MG requiring mechanical ventilation in 1991-1992 using the Nationwide Inpatient Survey (NIS) and compared these outcomes with homologous data from 2001-2002. NIS is the largest all-payer inpatient care database in the United States. RESULTS When comparing data from 2001-2002 with data from 1991-1992, we found a higher number of admissions for MG that required mechanical ventilation (994 vs. 652). The proportion of women was similar (53% vs. 60%). The average age (in years ± standard deviation) was significantly higher (65 ± 17 vs. 58 ± 18, p=0.0002). The length of hospitalization (in days ± standard deviation) was not different (22 ± 19 vs. 21 ± 16). Discharge to home occurred less frequently (29% vs. 60%, p=0.0001) and in hospital mortality minimally lower (13% vs. 15%). There was a significant increase in mean hospital charges ($118,000 vs. $84,100 adjusted for inflation, p=0.0001). In hospital mortality was higher among urban teaching hospitals compared with urban non teaching hospitals in 2001-2002. CONCLUSIONS Despite improvement in therapeutic strategies from 1991 to 2002, there was only a modest reduction in mortality and no substantial reduction of length of hospitalization for patients with MG requiring mechanical ventilation.