BACKGROUND
Sphincter preserving surgery (SPS) has been proposed as a quality measure for rectal cancer (RC) surgery. However, previous studies on SPS-rates lack critical clinical characteristics, rendering it unclear if variation in SPS-rates is due to unmeasured case-mix differences or surgeons’ selection criteria. In this context, we investigate the variation in SPS-rates at various practice settings.
METHODS
Ten hospitals in the Michigan Surgical Quality Collaborative collected RC-specific data including tumor location and reasons for non-SPS of patients who underwent RC surgery from 2007–2012. Hospitals were divided into terciles of SPS-rates (frequent, average and infrequent). Patients were categorized as “definitely SPS-eligible” a priori if they did not have any of the following: sphincter involvement, tumor <6cm from the anal verge, fecal incontinence, stoma preference or metastatic disease. Fixed-effects logistic regression was used to evaluate for factors associated with SPS.
RESULTS
In total, 329 patients underwent RC surgery at 10 hospitals (5/10 higher-volume and 6/10 major teaching). Overall, 72% had SPS (range by hospital 47%–91%). Patient and tumor characteristic were similar between hospital terciles. On multivariable analysis, only hospital ID, younger age, and tumor location were associated with SPS, but not sex, race, BMI, AJCC stage, preoperative radiation, or ASA class. Analysis of the 181 (55%) “definitely-eligible” patients revealed a SPS-rate of 90% (65–100%).
CONCLUSIONS
SPS-rates vary by hospital, even after accounting for clinical characteristics using detailed chart-review. These data suggest missed opportunities for SPS, and refute the general hypothesis that hospital variation in previous studies is due to unmeasured case-mix differences.