M. Arms1, J. W. McGillicuddy1, S. N. Nadig1, D. J. Taber1 1Medical University Of South Carolina,Transplant Surgery,Charleston, SC, USA
Introduction: Long-term graft survival in kidney transplant recipients remains sub-optimal. The impact of adverse drug events (ADEs) contributing to hospitalization and as a predominant risk factor for late graft loss has not been well-studied in this population.
Methods: This was a retrospective longitudinal cohort study of adult solitary kidney recipients transplanted between 2005 and 2010 with follow up through May 2016. Patients were divided into three cohorts: no readmissions, readmissions not due to an ADE, and ADEs contributing to readmissions. Medication regimens and progress notes were utilized to assess for ADE contribution to hospitalization using validated methodology. The rationale of the ADE contribution to the readmission was categorized in terms of probability, preventability, and severity. Predominant readmission etiologies across time, from 2005 to 2013 were compared to assess for temporal trends.
Results: 837 patients with 963 hospital readmissions were included in the study with a total follow up of 3,734 patient years (26 admissions per 100 patient years). Of the 837 patients, 47.9% had at least one hospital readmission during follow up; 65.0% of readmissions were deemed as having an ADE contribute to the readmission. The predominant causes of readmissions related to ADEs included non-opportunistic infections (39.6%), opportunistic infections (10.5%), acute rejection (18.1%) and acute kidney injury not related to rejection or infection (11.8%). From 2005 to 2013, readmissions over time due to under-immunosuppression significantly decreased at a rate of -1.6% per year, while readmission due to over-immunosuppression, as indicated by infection, cancer or cytopenias, significantly increased at a rate of 2.1% increase per year (difference 3.7%, p=0.026, see Figure 1). Significant risk factors for readmission related to an ADE included African American race, increased time on dialysis, increased time on waitlist and increased kidney donor profile index (KDPI). Protective factors included only being the recipient of a living donor kidney. Delayed graft function, acute rejection, serum creatinine, graft loss and death were all significantly higher in those with an ADE that contributed to a readmission, as compared to those with a readmission not due to an ADE or those that did not have a readmission during follow-up (p<0.05, see Table 1).
Conclusion: These results provide novel evidence demonstrating that ADEs contribute to a substantial number of readmissions after kidney transplant, which significantly increases the risk of graft loss and death, as compared to those readmitted for other causes or those without readmissions after transplant.
