Effects of patient factors on inpatient mortality after complex liver, pancreatic and gastric resections

BACKGROUND: There is mixed evidence that patients who receive care in hospitals with a low case volume for complex gastrointestinal and hepatobiliary operations have an increased risk of inpatient death. METHODS: A retrospective cohort study was performed of patients who had complex gastrointestinal and hepatobiliary operations in the Healthcare Cost and Utilization Project 2012 National Inpatient Sample. Multivariable weighted hierarchical generalized linear models were used to test the relationship between hospital case volume and probability of inpatient death, with detailed adjustments for the concurrent effects of differences in associated patient co‐morbidities. RESULTS: A total of 8260 pancreaticoduodenectomies, 2750 major hepatectomies and 3250 total gastrectomies were identified. Inpatient death occurred in 3·6 per cent of patients after pancreaticoduodenectomy, 4·9 per cent after major hepatectomy and 4·6 per cent after total gastrectomy. Mean hospital case volume was 50·6 (median 40) for pancreaticoduodenectomy, 23·6 (median 15) for major hepatectomy, 15·1 (median 10) for total gastrectomy and 70·2 (median 50) for any of the three operations. Hospital case volume was not a statistically significant predictor of mortality after any operation (all P ≥ 0·188). Patient characteristics including age and co‐morbidity were highly significant predictors of mortality (P < 0·001). No significant improvements in model performance were obtained by adding hospital case volume to any model that already included adjustments for patient‐level differences in age and co‐morbid disease, for any functional format (P ≥ 0·146 for all C statistic differences from baseline). CONCLUSION: Patient co‐morbidity, not hospital case volume, was associated with significant differences in inpatient mortality following complex gastric, pancreatic and hepatobiliary resections.