Trends of hospitalization for bipolar I in USA: A nationwide analysis

Objectives Bipolar II (B-II) is an important cause of morbidity and mortality in hospitalized patients. While B-II has been extensively studied in the past, the contemporary data for impact of B-II on cost of hospitalization are largely lacking. Methods We queried the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample (HCUP-NIS) dataset between 1998–2011 using the ICD-9 codes. Severity of comorbid conditions was defined by Deyo modification of Charlson comorbidity index. Primary outcome was in-hospital mortality and secondary outcome was total charges for hospitalization. Using SAS 9.2, Chi 2 test, t -test and Cochran-Armitage test were used to test significance. Results A total of 107,152 patients were analyzed; 62.61% were female and 31.39% were male ( P P P Conclusions While mortality has slightly increased from 1998 to 2011, the cost has significantly increased from $52.24 million/year to $1.6 billion/year, which leads to an estimated $1.55 billion/year additional burden to US health care system. In the era of cost conscious care, preventing B-II related hospitalization could save billions of dollars every year. Focused efforts are needed to establish preventive measures for B-II related hospitalization.