Effect of Minimum-Volume Standards on Patient Outcomes and Surgical Practice Patterns for Hysterectomy

To model the effect of implementing minimum-volume standards for women who underwent hysterectomy on patient outcomes and surgeon practice patterns.

We conducted a retrospective cohort study using the New York Statewide Planning and Research Cooperative System to capture data for all women who underwent hysterectomy from 2010 to 2014. We estimated the number of hysterectomies performed by each patient's physician during the prior year. Multivariable models were used to estimate the ratio of observed to expected complications based on each surgeon's volume during the prior year. The mean observed/expected ratio of surgeons was then plotted by volume. The number of patients and surgeons who would be eliminated and the reduction in complications if minimum-volume standards (lowest fifth and 10th percentiles) were implemented were analyzed. Separate analyses were performed for each route of hysterectomy.

We identified a total of 127,202 patients. For abdominal hysterectomy, increasing surgeon volume was associated with a decreasing rate of complications (P<.001). Overall, 17.5% of surgeons (n=1,260) had a prior year volume of one abdominal hysterectomy. The mean observed/expected ratio of surgeons with a prior year abdominal hysterectomy volume of one was 1.47 (SD 2.71). Within this group of surgeons, 31.4% had an observed/expected ratio of 1 or greater, indicating a higher than expected complication rate, and 68.7% of the surgeons had a observed/expected ratio of less than 1, suggesting a lower complication rate than expected based on case mix. Selection of a prior year volume standard of one would restrict 12.5% of surgeons performing robotic-assisted, 16.8% of those performing laparoscopic, and 27.6% of surgeons performing vaginal hysterectomy.

Implementing minimum-volume standards for hysterectomy, for even the lowest volume physicians, would restrict a significant number of gynecologic surgeons, including many with outcomes that are better than predicted.