Modeling and prediction of surgical procedure times

Accurate prediction of medical operation times is of crucial importance for cost-efficient operation room planning in hospitals. This paper investigates the possible dependence of procedure times on surgeon factors like age, experience, gender and team composition. The effect of these factors is estimated for over 30 different types of medical operations in two hospitals, by means of ANOVA models for logarithmic case durations. The estimation data set contains about 30,000 observations from 2005 to 2008. The relevance of surgeon factors depends on the type of operation. The factors found most often to be significant are team composition, experience and time of the day. Contrary to widespread opinions among surgeons, gender has nearly never a significant effect. By incorporating surgeon factors, the accuracy of out-of-sample prediction of case durations of about 1250 surgical operations in 2009 is improved by up to more than 15% compared with current planning procedures.