Incidence and impact of adverse drug events contributing to hospital readmissions in kidney transplant recipients

Background: The incidence and impact of adverse drug events (ADEs) leading to hospitalization and as a predominant risk factor for late graft loss has not been studied in transplantation. Methods: This was a longitudinal cohort study of adult kidney recipients transplanted between 2005 and 2010 and followed through 2013. There were 3 cohorts: no readmissions, readmissions not due to an adverse drug event, and adverse drug events contributing to readmissions. The rationale of the adverse drug events contribution to the readmission was categorized in terms of probability, preventability, and severity. Results: A total of 837 patients with 963 hospital readmissions were included; 47.9% had at least one hospital readmission and 65.0% of readmissions were deemed as having an ADE contribute. The predominant causes of readmissions related to ADEs included non-opportunistic infections (39.6%), opportunistic infections (10.5%), rejection (18.1%), and acute kidney injury (11.8%). Over time, readmissions due to under-immunosuppression (rejection) significantly decreased (−1.6% per year), while those due to over-immunosuppression (infection, cancer, or cytopenias) significantly increased (2.1% increase per year [difference 3.7%, P =.026]). Delayed graft function, rejection, creatinine, graft loss, and death were all significantly greater in those with an ADE that contributed to a readmission compared the other two cohorts (P <.05). Conclusion: These results demonstrate that ADEs may be associated with a significant increase in the risk of hospital readmission after kidney transplant and subsequent graft loss.