Surgeon and type of anesthesia predict variability in surgical procedure times

Background: Variability in surgical procedure times Increases the cost of h ealthcare delivery by increasing both the underutilization and overutilizat ion of expensive surgical resources. To reduce variability in surgical proc edure times, we must identify and study its sources. Methods: Our data set consisted of all surgeries performed over a 7-yr peri od at a large teaching hospital, resulting in 46,322 surgical cases. To stu dy factors associated with variability in surgical procedure times, data mi ning techniques were used to segment and focus the data so that the analyse s would be both technically and intellectually feasible. The data were subd ivided into 40 representative segments of manageable size and variability b ased on headers adopted from the common procedural terminology classificati on. Each data segment was then analyzed using a main-effects linear model t o identify and quantify specific sources of variability In surgical procedu re times. Results: The single most important source of variability in surgical proced ure times was surgeon effect. Type of anesthesia, age, gender, and American Society of Anesthesiologists risk class were additional sources of variabi lity. Intrinsic case-specific variability, unexplained by any of the preced ing factors, was found to be highest for shorter surgeries relative to long er procedures. Variability In procedure times among surgeons was a multipli cative function (proprotionate to time) of surgical time and total procedur e time, such that as procedure times increased, variability ill surgeons' s urgical time increased proportionately. Conclusions: Surgeon-specific variability should be considered when budding scheduling heuristics for longer surgeries. Results concerning variability in surgical procedure times due to factors such as type of anesthesia, age , gender, and American Society of Anesthesiologists risk class may be extra polated to scheduling In other Institutions, although specifics on individu al surgeons may not. This research identifies factors associated with varia bility in surgical procedure times, knowledge of which may ultimately be us ed to Improve surgical scheduling and operating room utilization.