Determinants of direct and indirect costs in anorexia nervosa

OBJECTIVE: To estimate direct and indirect costs of anorexia nervosa (AN), and to identify cost determinants.

METHODS: In a subsample (n = 225) of the ANTOP trial (Anorexia Nervosa Treatment of OutPatients) health care utilization and productivity losses were assessed at baseline for the previous 3 months and monetarily valued. Included were females aged 18 years and older diagnosed with AN or subsyndromal AN, and a body mass index (BMI) between 15 and 18.5 kg/m(2) . To account for missing data multiple imputation was employed. Cost determinants were derived from generalized linear models with gamma distribution and log link function.

RESULTS: Mean 3-months costs per patient amounted to €5,866 (SE = €576). The largest share of costs (€3,374) resulted from hospitalizations. Determinants of direct costs were analyzed separately for those with hospitalizations for AN, and those without. In the group only treated as outpatients, participants with binge/purge subtype, and those diseased for more than 6 years had higher costs. Moreover, costs were increased in patients with a comorbid mental disorder. In the group with hospitalizations, direct costs increased with BMI. BMI was measured at the end of the observation period, indicating that longer duration of treatment yielded higher weight gain. Indirect costs were not significantly associated with any disease-related characteristic.

DISCUSSION: Costs resulting from health care utilization and productivity loss are substantial, although the sample studied had not received sufficient treatment. Future research should analyze the development of costs over time.