THE RELATION BETWEEN TISS AND REAL PEDIATRIC ICU COSTS - A CASE-STUDYWITH GENERALIZABLE METHODOLOGY

Objective: To determine the quantitative relation between the Therapeu tic Intervention Scoring System (TISS) in combination with other relev ant clinical variables and the real costs of (paediatric) intensive ca re. Design: A prospective, observational study. Setting: A Ten-bed pae diatric intensive care unit in a university children's hospital. Patie nts and participants: In a 17-months registration period we collected patient- and treatment-related data for all 611 consecutive admissions . A 21-day calibration period was used to collect detailed data to cal culate the real costs of 33 consecutive admissions, in addition to the same data as in the registration period. Measurements and results: We used the Multi Moment Measurement method to measure time spent by nur ses and physicians and medication used in the 21-day calibration perio d. The calibration period data set with explanatory variables includin g TISS was used to build a regression model to estimate nurse and phys ician time, which were converted to personnel costs, and to estimate m edication costs. The regression models built from the calibration peri od were subsequently used to estimate the total costs per day and per admission in different patient groups in the registration period. Conc lusion: It was feasible to calculate total direct medical costs based on a limited number of readily available clinical variables related to patient characteristics and treatment, of which TISS was the most imp ortant determinant. The proposed methods provide further tools for ass essment of (paediatric) intensive care unit performance.