Anorexia Nervosa (AN) is an important cause of morbidity and mortality in hospitalized patients. While AN has been extensively studied in the past, the contemporary data for impact of AN 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 for AN. Severity of co-morbid conditions was defined by Deyo modification of Charlson co-morbidity index. Primary outcome was in-hospital mortality and secondary outcome was total charges for hospitalization. Using SAS 9.2, chi-square test, t-test and Cochran-Armitage test were used to test significance.

28,150 patients were analyzed. 93.94% were female and 6.06% were male (P < 0.0001). 88.67% were white, 2.93% were black and 8.4% were of other race (P < 0.0001). Rate of hospitalization decreased from 1530/million to 1349.5/million from 1998-2011. Overall mortality was 0.78% and mean cost of hospitalization was 25,829.82$. The in-hospital mortality reduced from 0.95% to 0.44% (P < 0.0001) and mean cost of hospitalization increased from 11,956.55$ to 39,831.51$. Total yearly spending on AN related admissions increased from $145.33 million/year to $420.61 million/year.

While mortality has slightly decreased from 1998 to 2011, the cost has significantly increased from $145.33 million/year to $420.61 million/year, which leads to an estimated $275.28 million additional burden to the US health care system. In the era of cost conscious care, preventing AN related Hospitalization could save billions of dollars every year. Focused efforts are needed to establish preventive measures for AN related hospitalization.

The authors have not supplied their declaration of competing interest.