Hospital-free days in the first year after lung transplantation and subsequent survival

Abstract

Background: Complications occurring during the first postoperative year after lung transplantation increase the risk of long-term mortality. These events often lead to prolonged and repeated hospitalizations. We sought to assess the relationship between days outside the hospital or hospital-free days (HFD) during the first post-transplant year among 1-year survivors and subsequent retransplant-free survival. Methods: In a single-center study, we derived total inpatient days (initial transplant episode, readmission, and emergency room/observation) from the electronic medical record of lung transplant recipients who survived 1 year. The cohort was divided into HFD quartiles and Kaplan-Meier curves of subsequent transplant-free survival were compared with log-rank analysis. A Cox proportional hazards model was used to test the association of HFD with outcome and adjusted for selected variables. Results: Among 238 patients, 42 deaths and 2 retransplants occurred after a median of 3.6 years post-transplant. The median HFD was 341 (interquartile range: 324, 348). Estimated transplant-free survival at 3 and 5 years post-transplant in the lowest quartile of HFD (79% and 56%, respectively) was considerably worse compared with the first quartile (98% and 94%; p < 0.01). Fewer HFD were associated with subsequent death or retransplant [hazard ratio: 0.90 (95% confidence interval: 0.85, 0.94; p < 0.001) for each 10-day increase] and remained significant after adjusting for several potentially confounding variables. Conclusions: HFD during the first year after lung transplantation is a predictor of subsequent long-term outcomes and may be a useful surrogate marker for clinical trials during the early postoperative period.

Keywords

• hospital-free days
• survival
• lung transplant
• readmissions
• length of hospital stay