Background. The age of a liver transplant (LT) candidate is one of many variables used in the transplant selection process. Most research about the age at transplant has used prespecified age ranges or categories in assessing associations with transplant outcomes. However, there is a lack of knowledge about the age at transplant and survival. This study aimed to examine associations of age at transplant as a continuous variable, in conjunction with other patient and disease-related factors, with patient and graft survival after LT. Methods. We used the Standard Transplant Analysis and Research data to identify LT recipients between January 2002 and June 2018. Cox regression models with a restricted cubic spline term for age examined associations with graft and patient survival after LT. We assessed the interactions of age with recipients’ sex, race/ethnicity, region, indication for transplant, body mass index, model for end-stage liver disease score, diabetes, functional status at transplant, and donor risk index. Results. Age at the time of LT showed a nonlinear association with both graft and patient survival. Each demographic, clinical, transplant-related, and donor-related factor influenced these relationships differently. Conclusions. Our results suggest that some older LT candidates may be better than some younger candidates and that clinicians should not exclusively use age to determine who receives LT.
Impact of County Health Rankings on Nationwide Liver Transplant Outcomes
Background. There is limited information concerning whether social determinants of health affect postliver transplant (LT) outcomes. This study aims to understand to what extent the health of LT recipients’ counties of residence influence long-term LT outcomes. Methods. We used the United Network for Organ Sharing data to identify adult LT recipients transplanted between January 2010 and June 2018. Patient-level data were matched to county-level County Health Ranking (CHR) data using transplant recipient zip code, and nationwide CHRs were created. Mixed-effects Cox proportional hazards models were used to examine associations between CHRs and graft and patient survival post-LT. Results. Health outcomes rank was significantly associated with posttransplant graft and patient survival, with worst tertile counties showing a 13% increased hazard of both graft failure and patient mortality compared to the best tertile counties. Conclusions. Although county health is associated with LT outcomes, it also appears that LT recipient selection is effective at mitigating major disparities based on county of residence and helps yield equitable outcomes in this respect.