Analysis of Turnaround Times in Pathology

This article introduces the use of failure time analysis methods for studying turnaround times in pathology. The key to understanding the approach is to view a laboratory specimen like a living patient. When the specimen enters the laboratory, the time is analogous to the time of diagnosis for a patient. When the specimen’s analysis is completed, the event is analogous to a patient who has died. To illustrate the approach, I use data previously published and data generated at the Durham, NC, Veterans Affairs Medical Center. I demonstrate that the Kaplan-Meier plotting method, the log-rank test, and the Cox model can all be applied to turnaround times and provide useful results.