A history of chronic opioid usage prior to kidney transplantation may be associated with increased mortality risk

Chronic opioid usage (COU) for analgesia is common among patients with end-stage renal disease. In order to test whether a prior history of COU negatively affects post-kidney transplant outcomes, we retrospectively examined clinical outcomes in adult kidney transplant patients. Among 1064 adult kidney transplant patients, 452 (42.5%) reported the presence of various body pains and 108 (10.2%) reported a prior history of COU. While the overall death or kidney graft loss was not statistically different between patients with and without a history of COU, the cumulative mortality rate at 1, 3, and 5 years after transplantation, and during the entire study period, appeared significantly higher for patients with than without a history of COU (6.5, 18.5, and 20.4 vs. 3.2, 7.5, and 12.7%, respectively). Multivariate Cox regression analysis adjusted for potential confounding factors in entire cohorts and Cox regression analysis in 1:3 propensity-score matched cohorts suggest that a positive history of COU was significantly associated with nearly a 1.6- to 2-fold increase in the risk of death (hazard ratio 1.65, 95% confidence interval 1.04-2.60, and hazard ratio 1.92, 95% confidence interval 1.08-3.42, respectively). Thus, a history of chronic opioid usage prior to transplantation appears to be associated with increased mortality risk. Additional studies are warranted to confirm the observed association and to understand the mechanisms.