Functional status predicts postoperative mortality after liver transplantation

Abstract

Background: Frail patients are more vulnerable to perioperative stressors of liver transplantation (LT). Program Specific Reports, used in transplant center auditing, risk-adjust for frailty using the Karnofsky Performance Status (KPS) scale. We evaluate the extent to which functional impairment/disability is associated with increased risk of postoperative death.

Methods: We included 24 505 first-time LT recipients from the Scientific Registry of Transplant Recipients (2006-2011). We categorized patients as Severe, Moderate, or Normal function/disability using the KPS scale and evaluated risk of 30- and 90-day mortality. Analyses took potential center-specific differences in KPS measurement protocols into account using hierarchal logistic modeling.

Results: Over one-quarter of our population was Severely impaired/disabled, and 30.5% had no functional limitations. Severely and Moderately impaired/disabled patients had 2.56 (95% CI 1.91-3.44) and 1.40 (95% CI 1.10-1.78) times the odds of 30-day mortality, respectively, after adjusting for key recipient and donor factors. Estimates remained consistent regardless of Model for End-Stage Liver Disease score, medical condition, or clustering analyses by center. Technical/operative complications and multiorgan failure/hemorrhage were more common causes of death among more Severely disabled patients than in higher functioning groups.

Conclusions: Pre-transplant functional status, assessed using the KPS scale, is a reliable predictor of post-LT mortality in the United States.

Keywords: Karnofsky Performance Status; disability evaluation; end-stage liver disease; liver transplantation; mortality; organ transplants; risk factors.