Impact of interhospital transfer on clinical outcomes and resource use after cardiac operations: Insights from a national cohort.

Background: Interhospital transfer is a common clinical practice that has been associated with poor patient outcomes in small series. We aimed to evaluate the impact of transfer status on cardiac surgery patients in a national cohort.

Methods: Patients undergoing nonelective coronary artery bypass grafting, valve replacement or repair, or a combination were identified using the 2010 to 2017 Nationwide Readmissions Database. Patients were stratified by transfer status and outcomes were evaluated using adjusted multivariable linear and logistic models.

Results: Of an estimated 1,023,315 patients, 170,319 (16.6%) were transfers. Transfer was independently associated with increased complications, index hospitalization duration of stay, costs, early (30 day), and intermediate (31-90 day) readmission. Among transferred patients, transfer to a high-volume center predicted reduced odds of mortality (adjusted odds ratio: 0.64, P < .001). Additionally, transfers were less likely to be readmitted back to the index hospital (80.7% vs 44.9%, P < .001).

Conclusion: Transfer status is a significant independent predictor of increased complications, length of stay, cost, and readmission among nonelective cardiac surgery patients. Notably, transfer to higher volume facilities appears to increase odds of survival. Our findings are important when considering the risks involved in the management of transferred patients.