Association of travel distance, hospital volume and peri-operative outcomes following resection of gallbladder adenocarcinoma

Abstract

Background: The effect of hospital/surgeon volume and travel distance on patient outcomes after major abdominal surgery remains poorly defined. We characterized the relationship among travel distance, hospital volume and long-term outcomes after resection of gallbladder adenocarcinoma. Methods: The 2004–2015 National Cancer Database was used to identify patients who underwent resection of gallbladder adenocarcinoma. Patients were stratified according to travel distance and hospital volume quartiles and multivariable Cox regression models were utilized to examine the impact of travel distance, hospital volume and travel distance/hospital volume on overall survival. Results: Among 11,559 patients identified with gallbladder adenocarcinoma, the most commonly performed procedure was total removal of the primary site (N = 7,605, 65.7%). Median patient age was 71 years (IQR 62–80); most patients were female (N = 8,081, 69.9%) and white (N = 9,301, 80.4%). Stratifying data into quartiles, travel distance to surgical care was: ≤3.6 miles, >3.6-8.1 miles, >8.1–21.3 miles, and ≥21.3 miles. Overall hospital quartile volumes were 1–9 cases/year, 5-9 cases/year, 10–22 cases/year, and ≥ 23 cases/year. White patients who had private insurance, as well as patients with more advanced pathological T and N stage disease, were more likely to travel further for surgical care (all p < 0.001). On multivariable analysis, after controlling for factors except hospital volume, a longer travel distance was associated with a lower risk of death long-term (HR 0.91, 95% CI 0.84–0.98, p < 0.001). The association of travel distance with overall survival was mediated through hospital volume as only hospital volume was associated with survival (HR 1.15, 95% CI 1.04–1.27, p = 0.007) after controlling for both travel distance and hospital volume. Conclusion: Roughly 1 in 5 patients with gallbladder cancer travelled more than 20 miles for surgical care. Longer travel distance was more common among white patients with private insurance. Increased travel distance was associated with improved overall survival with the association likely mediated through the effect of hospital volume.