We compared centralized vs distributed methods for delivering 'stat' test results for blood gas, glucose, and electrolyte assays. The parameters for comparison were as follows: (a) laboratory turnaround time (TAT), (b) therapeutic TAT, and (c) staff satisfaction. Therapeutic TAT, defined as the time from the initiating order to the receipt of the result and the implementation of any indicated change in treatment, was obtained by direct observation of testing procedures at the bedside and timing each step in the process. Observing therapeutic TAT yields information on the impact of laboratory testing methods in the context of clinical decision making. Therapeutic TAT was 1-2 min shorter for bedside testing compared with a satellite laboratory and 9-14 min shorter in the satellite laboratory compared with centralized testing. Satellite laboratories received the highest staff satisfaction scores, followed by bedside testing, with the central laboratory receiving the lowest scores.