Use of Historic Surgical Times to Predict Duration of Hysterectomy: Stratifying by Uterine Weight

STUDY OBJECTIVE: To describe the accuracy of historic averages for estimating operating room (OR) time for hysterectomy among women with small and large uteri. DESIGN: A retrospective cohort study. SETTING: Data from women who underwent abdominal, vaginal, or laparoscopic hysterectomy between 2015 and 2017 at the University of North Carolina Hospitals were analyzed. Historic and actual OR times were compared using linear regression. Patient characteristics were also evaluated to determine whether they were associated with the accuracy of predicted OR times. PATIENTS: Nine hundred eighty-five adult women (≥18 years old) who underwent surgery for benign indications or for suspected but not biopsy-confirmed malignancy were included. INTERVENTIONS: Not applicable. MEASUREMENTS AND MAIN RESULTS: Historic averages overestimated OR time by a median of 14 minutes (interquartile range [IQR] = -29 to 49 minutes). The OR time in women with small uteri (<250 g) was significantly more likely to be overestimated than women with large uteri (≥250 g) (median time = 21 minutes [IQR = -16 to 52 minutes] and 3 minutes [IQR = -38 to 44 minutes], respectively; p <. 001). In total laparoscopic hysterectomy and laparoscopy-assisted vaginal hysterectomy, women with uteri ≥250 g took significantly longer than hysterectomy for women with uteri <250 g (36 minutes longer [95% confidence interval, 24-50] and 95 minutes longer [95% confidence interval, 12-179], respectively; p < .001 and p = .03). CONCLUSION: Using historic averages overestimates OR time, and it is more pronounced in women with small uteri. However, there is a relatively large range of OR times, even among women with the same size uteri. This study highlights the importance of preoperative planning, and in cases in which endometriosis is expected, manually adding time to estimates is recommended.