Abhijit S Naik, Vikas R Dharnidharka, Mark A Schnitzler, Daniel C Brennan, Dorry L Segev, David Axelrod, Huiling Xiao, Lauren Kucirka, Jiajing Chen, Krista L Lentine

We examined United States Renal Data System registry records for Medicare-insured kidney transplant recipients in 2000-2011 to study the clinical and cost impacts of urinary tract infections (UTI), pneumonia, and sepsis in the first year post-transplant among a contemporary, national cohort. Infections were identified by billing diagnostic codes. Among 60,702 recipients, 45% experienced at least one study infection in the first year post-transplant, including UTI in 32%, pneumonia in 13%, and sepsis in 12%. Older recipient age, female sex, diabetic kidney failure, non-standard criteria organs, sirolimus-based immunosuppression and steroids at discharge were associated with increased risk of first-year infections. By time-varying, multivariate Cox regression, all study infections predicted increased first-year mortality, ranging from 41% (aHR 1.41, 95%CI 1.25-1.56) for UTI alone, 6-to-12-fold risk for pneumonia or sepsis alone, to 34-fold risk (aHR 34.38, 95%CI 30.35-38.95) for those with all three infections. Infections also significantly increased first-year costs, from $17,691 (standard error (SE) $591) marginal cost increase for UTI alone, to approximately $40,000-$50,000 (SE $1054-1238) for pneumonia or sepsis alone, to $134,773 (SE $1876) for those with UTI, pneumonia and sepsis. Clinical and economic impacts persisted in years 2-3 post-transplant. Early infections reflect important targets for management protocols to improve post-transplant outcomes and reduce costs of care. This article is protected by copyright. All rights reserved.