Days alive and out of hospital and graft survival after living donor liver transplantation

BACKGROUND: Days alive and out of hospital (DAOH) is a simple metric representing the number of days not in hospital within a defined postoperative period. In a case of mortality within the defined period, the DAOH is considered zero. DAOH has been validated in various surgical procedures, but not in living donor liver transplantation (LDLT). This study aimed to demonstrate correlation between DAOH and graft failure after LDLT. METHODS: In this cohort study, we identified 1,335 adult-to-adult LDLT performed from June 1997 to April 2019 in our institution. We calculated DAOH at 30, 60, and 90 days among survivors and divided the recipients according to the estimated threshold of each defined period. RESULTS: The median duration of hospital stay after LDLT in the entire population was 25 (interquartile 22–41) days. Mean DAOH of survivors at 30, 60, and 90 days were 3.3 (±3.9), 19.7 (±15.9), and 40.3 (±26.3) days, respectively. We estimated the thresholds associated with three-year graft failure for DAOH at 30, 60, and 90 days and they were 1, 12, and 42 days, respectively. The incidence of graft failure was higher in recipients with short DAOH than long DAOH (10.9% vs. 23.6%, 10.3% vs. 24.3%, and 9.3% vs. 22.2% for DAOH at 30, 60, and 90 days, respectively). Among survivors at 60 days, recipients with short DAOH showed significantly higher incidence of three-year graft failure [hazard ratio (HR), 2.49; 95% confidence interval (CI): 1.86–3.34; P<0.001]. CONCLUSIONS: Considering clinical situations after LDLT, DAOH at 60 days may be a valid outcome measure.