Karnofsky performance status before and after liver transplantation predicts graft and patient survival

Abstract

The Karnofsky performance status (KPS) has been used for almost 70 years for clinical assessment of patients. Our objective was to determine whether KPS is an independent predictor of post-liver transplant (LT) survival after adjusting for known confounders. Adult patients listed with the United Network for Organ Sharing (UNOS) from 2006 to 2016 were grouped into low (10-40%, n = 15,103), intermediate (50-70%, n = 22,183) and high (80-100%, n = 13,131) KPS groups based on KPS scores at the time of LT, after excluding those on ventilators or life support. We determined the trends in KPS before and after LT, and survival probabilities based on KPS. There was a decline in KPS scores between listing and LT and there was significant improvement after LT. The graft and patient survival differences were significantly lower (p <0.0001) in those with low KPS. After adjusting for other confounders, the hazard ratios for graft failure were 1.17 (1.12-1.22, p <0.01) for the intermediate and 1.38 (1.31-1.46, p <0.01) for the low group. Similarly, hazard ratios for patient failure were 1.18 (1.13-1.24, p <0.01) for the intermediate and 1.43 (1.35-1.52, p <0.01) for the low group. Other independent negative predictors for graft and patient survival were older age, Black ethnicity, presence of hepatic encephalopathy and donor risk index. Those who did not show significant improvements in post-LT KPS scores had poorer outcomes in all three KPS groups, but it was most obvious in the low KPS group with one-year patient survival of 33%. The KPS, before and after LT, is an independent predictor of graft and patient survival after adjusting for other important predictors of survival. The overall health of liver transplant recipients could be assessed by a simple clinical assessment tool called the Karnofsky performance status, which assesses an individual's overall functional status on an 11-point scale, in increments of 10, where a score of 0 is considered dead and 100 is considered perfect health. In this study, using a large dataset, we show that the performance status before and after liver transplant is a predictor of survival. More importantly, those who have low performance status before transplant and do not show an improvement in performance status between 3-12 months after liver transplant have very poor survival.