Preanalytic Delays as a Component of Test Turnaround Time

The time required to requisition, collect, and transport specimens to the laboratory was measured at two institutions using an observer stationed on patient wards and in the laboratory. For both routine and stat tests, preanalytic delays were significantly longer than within-laboratory delays at the two institutions. For routine tests, the interval between completion of the test requisition and collection of the specimen was the single largest contributor to preanalytic delays, accounting for 82% and 89% of the preanalytic interval. In addition, it was found that the time of specimen collection and laboratory accessioning recorded in the hospitals’ computer systems were not accurate. In one of the hospitals studied, stat specimens arrived in the laboratory an average of 32 minutes before the accessioning time recorded in the hospital computer system. These data suggest that a substantial proportion of turnaround time delays occur before specimens reach the laboratory and that efforts to speed up turnaround time might be more profitably directed at reducing preanalytic delay than improving within-laboratory speed. The data also suggest that times recorded in hospital information systems may not be reliable for monitoring turnaround time and should be validated with observational studies before being used to generate automated turnaround time reports.