Retrospective Cohort Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Transplant. Nov 20, 2019; 9(7): 145-157
Published online Nov 20, 2019. doi: 10.5500/wjt.v9.i7.145
Impact of recipient functional status on 1-year liver transplant outcomes
Natasha H Dolgin, Babak Movahedi, Frederick A Anderson, Isabel MA Brüggenwirth, Paulo N Martins, Adel Bozorgzadeh
Natasha H Dolgin, Babak Movahedi, Paulo N Martins, Adel Bozorgzadeh, Department of Surgery, Division of Organ Transplantation, UMass Memorial Medical Center, University of Massachusetts Medical School, Worcester, MA 01605, United States
Natasha H Dolgin, Department of Quantitative Health Sciences, Clinical and Population Health Research Program, University of Massachusetts Medical School, Worcester, MA 01605, United States
Natasha H Dolgin, Frederick A Anderson, Department of Surgery, Center for Outcomes Research, University of Massachusetts Medical School, Worcester, MA 01655, United States
Isabel MA Brüggenwirth, Department of Surgery, Section of Hepatobiliary Surgery and Liver Transplantation, University Medical Center Groningen, University of Groningen, Groningen 9713GZ, Netherlands
Author contributions: Dolgin NH, Movahedi B, Anderson FA, Brüggenwirth IMA, Martins PN, and Bozorgzadeh A participated in research design; Dolgin NH, Movahedi B, Martins PN, and Bozorgzadeh A analyzed data; Anderson A provided analytic tools; Dolgin NH, Martins PN, and Bozorgzadeh A wrote the paper; Brüggenwirth IMA, Martins PN, and Bozorgzadeh A revised the manuscript; Martins PN and Bozorgzadeh A made the equal contribution.
Institutional review board statement: This study was deemed exempt by the University of Massachusetts Medical School Institutional Review Board.
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous data that were obtained from the Scientific Registry of Transplant Recipients (SRTR). The SRTR is contracted to UNOS by the United States Department of Health and Human Services to manage data collected via government-mandated reporting by all United States transplant centers.
Conflict-of-interest statement: All the Authors have no conflict of interest related to the manuscript.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Natasha H Dolgin, MD, PhD, Doctor, Department of Surgery, Division of Organ Transplantation, UMass Memorial Medical Center, University of Massachusetts Medical School, 55 Lake Avenue, Worcester, MA 01655, United States. natasha.dolgin@gmail.com
Telephone: +1-781-6089635
Received: March 26, 2019
Peer-review started: March 26, 2019
First decision: March 26, 2019
Revised: October 16, 2019
Accepted: November 6, 2019
Article in press: November 6, 2019
Published online: November 20, 2019
Processing time: 238 Days and 13.5 Hours
ARTICLE HIGHLIGHTS
Research background

Frailty is increasingly recognized as an important predictor of outcomes after major surgical procedures including liver transplantation. The Karnofsky Performance Status (KPS) scale has been widely validated for clinical practice for over 60 years.

Research motivation

To investigate the impact of frailty on liver transplant outcomes.

Research objectives

We wanted to determine the extent to which poor pre-transplant functional status, assessed using the KPS scale, is associated with increased risk of mortality and/or graft failure at 1-year post-transplantation. This would give clinicians some objective assessment and help on the decision to allocate livers for high-risk recipients.

Research methods

This study included 38278 United States adults who underwent first, non-urgent, liver-only transplantation from 2005 to 2014 (Scientific Registry of Transplant Recipients). Functional impairment/disability was categorized as severe (10%-40% of optimal function), moderate (50%-70%), or none/normal (80%-100%). Analyses were conducted using multivariable-adjusted Cox survival regression models. We explored bivariate relationships between the primary exposure (functional status) and potential confounders of interest using contingency table analyses [chi-squared tests for categorical variables, ANOVA for continuous variables, and Spearman's rho (rs) for ordered-variable correlations, using expanded KPS, continuous Model for End-Stage for Liver Disease (MELD)]. Relationships between variables and post-transplant time were explored graphically. One-year cumulative failure rates were estimated using the Kaplan Meier method.

Research results

The median age was 56 years, 31% were women, median pre-transplant MELD was 18. Functional impairment was present in 70%; one-quarter of the sample was severely disabled. After controlling for key recipient and donor factors, moderately and severely disabled patients had a 1-year mortality rate of 1.32 [confidence interval (CI): 1.21-1.44] and 1.73 (95%CI: 1.56-1.91) compared to patients with no impairment, respectively. Subjects with moderate and severe disability also had a multivariable-adjusted 1-year graft failure rate of 1.13 (CI: 1.02-1.24) and 1.16 (CI: 1.02-1.31), respectively.

Research conclusions

Pre-transplant functional status is a useful prognostic indicator for 1-year post-transplant patient and graft survival. It is important to continue to develop objective measures for describing global health status and illness severity to help in the allocation of organs and waitlist management, patient health improvement, and accurate adjustment for transplant center case-mix for transplant reimbursement. We present data from the first national study illustrating the role of pre-transplant functional status as a predictor of one-year survival among liver transplant recipients. Our results are in agreement with the findings from earlier studies that evaluated Poor functional status as a predictor of adverse transplant outcomes. We have not proposed any theory. The index of frailty - The KPS scale - can be used as a predictor of 1-year post-transplant outcomes (patient and graft survival) in a national United States liver transplant population. Poor functional status predicts 1-year post-liver transplant outcomes. No new methods were proposed. We used very well-established methods of outcome research. It will help to determine objective measures for describing frailty and overall clinical status to help in the allocation of organs and waitlist management, patient health improvement, transplant reimbursement, and policy changes.

Research perspectives

That patients’ pre-transplant frailty plays a critical role in transplant outcomes and the transplant community need to study it with more detail. To perform prospective and randomized studies associating frailty index with other biomarkers and correlate them with transplant outcomes. Associating frailty indexes with other biomarkers and correlate them with transplant outcomes. To measure the impact of interventions to improve frailty pre-transplant and correlate it with outcomes.