OBJECTIVE: So far only five randomized controlled trials on acute day hospital care have assessed direct health care costs and compared these with costs of conventional inpatient treatment. This paper aims to close this research gap for German speaking countries.

METHOD: Another trial was conducted at the Department of Psychiatry and Psychotherapy, Dresden University of Technology. Using the Client Service Receipt Inventory interviews with patients at three time-points (admission, discharge, three months after discharge) assessed their utilization of health care services. Based on the results of a separate regional cost-calculation project, costs of individual care packages could be calculated. 144 patients (day care: n = 75, inpatient care: n = 69) with complete data sets for all time-points of assessment were included in the intention-to-treat-analysis. Means of direct costs (given in Euro and referred to Deutsche Mark prices in 2000) were computed, and t-tests and bootstrap-procedures were used for group comparison. Furthermore, missing and sensitivity analyses were conducted.

RESULTS: Patients in the acute day hospital caused mean direct health care costs of 12 401 per person within the entire period assessed. Thus, their cost level falls below the mean costs of inpatient care (15,924 euro per person) by 22.1 %. Missing analyses showed no selection effects on cost results caused by patients who could not be assessed at all defined time-points. Costs for inpatient and day care services were the most sensitive parameters for maintaining the statistically significant differences of cost means demonstrated between the two study groups.

CONCLUSION: For German-speaking countries, this study shows for the first time that acute day care -- which has been demonstrated to be clinically at least as effective as inpatient care - is the less expensive option if these two settings are comparatively assessed.