Estimating the duration of a case when the surgeon has not recently scheduled the procedure at the surgical suite

For some scheduled cases, there may be no previous cases of the same proced ure type by the same surgeon for use in estimating the duration of the new case. We evaluated which of 16 different methods of analysis of other surge ons' eases of the same procedure type resulted in the most accurate predict ion of the duration of the case that the surgeon had not recently scheduled . We analyzed durations for 4,955 cases, from an operating room information system, for which a surgeon had only scheduled the procedure once, and for which other surgeons had scheduled that same procedure one or more times. Using these data, we determined the difference between the actual duration of the new case and the estimated duration of the new case as calculated by each of the methods (average absolute error of 1.1 h with average case dur ation of 3.1 h). Implications: When no recent historical time data are avai lable for a surgeon doing a given procedure, the mean of the durations of c ases of the same scheduled procedure per formed by other surgeons is as acc urate an estimate as more sophisticated analyses. More research is needed t o improve the precision of estimates of case durations.