Patient and hospital factors associated with use of sphincter-sparing surgery for rectal cancer.

PURPOSE: Sphincter-sparing surgery for rectal cancer is associated with higher patient satisfaction, equivalent oncologic outcomes, and less morbidity than abdominoperineal resection. No national studies have explored trends in the use of sphincter-preserving rectal resection, while accounting for both hospital and patient factors.
METHODS: This is a retrospective cohort study of 47,713 patients from the Nationwide Inpatient Sample who underwent surgery for rectal cancer from 1988 to 2006. Univariate analysis was used to identify patient and hospital factors associated with sphincter preservation. Logistic regression was performed to control for confounding variables. Trends in use of sphincter-sparing surgery over time were examined to identify hospital factors associated with higher rates of adoption.
RESULTS: Patient demographics associated with sphincter preservation in multivariate analysis were age <60, female gender, and white race. Among hospital factors associated with sphincter preservation, the most important predictors were high procedural volume (odds ratio 1.55; 95% CI 1.33-1.79; P < .001), and urban location (odds ratio 1.26; 95% CI 1.33-1.40; P < .001). Although sphincter preservation increased over time in the entire cohort (35.4% in 1988 vs 60.5% in 2006), high-volume hospitals had significantly higher rates of sphincter preservation compared with the lowest-volume hospitals.
CONCLUSIONS: Although rates of adoption of sphincter-sparing surgery were similar across hospital volume strata, overall rates of sphincter preservation were consistently higher in high-volume and urban hospitals, and among patients who are female, white, and younger. Further research is needed to determine whether these differences reflect disparities in quality of surgical care, or differences in referral patterns or case mix.