Association between hospital volume and mortality after elective oesophageal cancer resection in Switzerland: a retrospective national registry study from 2013 to 2022

PURPOSE: The association between a high annual hospital-specific case volume and improved postoperative outcomes after oesophageal cancer resection (OCR) is well described. The Swiss government started centralisation of OCR in 2013. This study investigates this centralisation in terms of the annual hospital-specific case volume of OCR (hospital volume) and its effect on short-term postoperative outcomes. METHODS: National inpatient registry data of all hospitals providing OCR (ICD codes C15 and at least one of the CHOP codes starting with 424, 425, or 426) between 2013 and 2022 in Switzerland were analysed. The primary endpoint was in-hospital mortality. Secondary endpoints were postoperative complications and length of hospital stay (LOS). RESULTS: 1'535 cases were identified. The annual number of hospitals providing OCR ranged between 30 in 2013 and 14 in 2021. Hospital volume varied between one and 40 patients per year. Overall mortality was 5.3% (n = 81) declining from 9.3% in 2013 to 3.8% in 2022 (t=-0.511, p = 0.040). Increasing hospital volume was associated with lower risk for mortality (odds ratio (OR) = 0.723, 95% confidence interval (CI) 0.53 to 0.98, p = 0.037) and postoperative complications (OR = 0.705, 95%CI: 0.62 to 0.83, p < 0.001). There was no association of hospital volume with LOS (β = 0.007, 95%CI -0.093 to 0.108, p = 0.889). However, there were significant differences across quantiles (joint p < 0.001). CONCLUSIONS: Higher hospital volume is associated with lower mortality and fewer postoperative complications following OCR, whereas no association was observed with LOS. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT07022652, https://clinicaltrials.gov/search?id=NCT07022652.