Schizoaffective disorder (SD) is an important cause of morbidity and mortality in hospitalized patients. While SD has been extensively studied in the past, the contemporary data for impact of SD on cost of hospitalization are largely lacking.

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, Chi² test, t-test and Cochran-Armitage test were used to test significance.

A total of 4,66,800 patients were analyzed; 50.90% were female and 49.10% male (P<0.0001); 61.15% were white, 25.97% black and 12.88% of other race (P<0.0001). Rate of hospitalization increased from 13,035.05/million to 26,703.21/million from 1998–2011. Overall mortality was 0.50% and mean cost of hospitalization was 20,995.19$. The in-hospital mortality increased from 0.46% to 0.50% (P<0.0001) and mean cost of hospitalization increased from 11,504.94$ to 31,460.67$. Total spending on SD related admissions increased from $1.2 billion/year to $6.6 billion/year.

While mortality has slightly increased from 1998 to 2011, the cost has significantly increased from $1.2 billion/year to $6.6 billion/year which leads to an estimated $5.4 billion/year additional burden to US health care system. In the era of cost conscious care, preventing SD related hospitalization could save billions of dollars every year. Focused efforts are needed to establish preventive measures for SD related hospitalization.