Comparison of Rates and Outcomes of Readmission to Index vs Nonindex Hospitals After Major Cancer Surgery

Importance: Increasing regionalization of cancer surgery has the inadvertent potential to lead to fragmentation of care if readmissions occur at a facility other than the index hospital. The magnitude and adverse effects of readmission to a facility other than the one where the surgery was performed are unclear. Objectives: To assess rates of readmission to nonindex hospitals after major cancer surgery and to compare outcomes between index and nonindex hospital readmissions. Design, Setting, and Participants: In this multicenter, population-based, nationally representative study of adult patients undergoing a major cancer operation (defined as esophagectomies or gastrectomies, hepaticobiliary resections, pancreatectomies, colorectal resections, or cystectomies), retrospective analyses were performed using the Nationwide Readmissions Database (admissions from January 1 through September 30, 2013). Descriptive analyses were performed to determine 90-day readmission characteristics, including timing, cost, and outcomes. Adjusting for clustering by facility, the study used multivariate logistic regression to identify factors associated with nonindex vs index readmissions. The study also used regression models to identify differences in mortality, major complications, and subsequent readmissions between the 2 groups. Data analysis was performed from January 1 through December 31, 2013. Exposures: Readmission to index vs nonindex hospitals (defined as any hospital other than the hospital where the major cancer operation was performed). Main Outcomes and Measures: Proportion of 90-day readmissions and nonindex readmissions after major cancer surgery, factors associated with nonindex readmissions, and difference between in-hospital mortality, hospital costs, and subsequent readmissions for patients admitted to index vs nonindex hospitals. Results: A total of 60 970 patients were included in the study (mean SD age, 67 13 years; 7619 55.6% male and 6075 44.4% female). The 90-day readmission rate was 23.0%. Of the 13 695 first readmissions, 20.1% were to a nonindex hospital. Independent factors associated with readmission to a nonindex hospital included type of procedure, comorbidities (OR, 1.40; 95% CI, 1.15-1.70), elective admission (OR, 1.21; 95% CI, 1.06-1.37), discharge to a nursing facility (OR, 1.20; 95% CI, 1.07-1.36), and surgery at a teaching hospital (OR, 1.16; 95% CI, 1.00-1.34) (all P < .05). After risk adjustment, patients readmitted to nonindex hospitals had 31.2% higher odds of mortality (odds ratio, 1.31; 95% CI, 1.05-1.64) and 27.3% higher odds of having a major complication (odds ratio, 1.27; 95% CI, 1.14-1.42). Subsequent readmissions and hospital costs were not different between the 2 groups. Conclusions and Relevance: Approximately one-fifth of readmissions were to a nonindex hospital and were associated with higher mortality and morbidity than readmission to index hospitals. Factors that influence nonindex readmissions have been identified to target interventions.