Understanding medical care of transplant recipients through integrated registry and pharmacy claims data

Background: Limited data exist on medication use aside from immunosuppression among large samples of kidney transplant recipients. Methods: We examined a novel database wherein Organ Procurement and Transplantation Network (OPTN) registry data were linked to records from a US pharmaceutical claims clearinghouse (2005-2010 claims) to examine pharmaceutical care at the first transplant anniversary (n = 16,157). We quantified the use of the following medication types within ±60 days of the first-year OPTN report according to estimated glomerular filtration rate (eGFR): antihypertensives, lipid-lowering, bone and mineral, and anemia treatments. Adjusted associations of medication use with eGFR and other clinical factors were quantified by multivariate logistic regression. Results: Requirements for multiple antihypertensive agents rose with lower eGFR, with β-blockers comprising the most commonly used antihypertensive agent. The adjusted likelihood of vitamin D (adjusted odds ratio (aOR) 2.07, 95% CI 1.19-3.59) and especially erythrocyte-stimulating agents (aOR 19.94, 95% CI 7.01-56.00) rose in a graded manner to peak with eGFR <15 versus >90, whereas statin use was most common with eGFR 30-59 ml/min/1.73 m². Black race was independently associated with increased use of all classes of antihypertensives and vitamin D, but lower adjusted statin use. Rapamycin-based immunosuppression was associated with increased use of statins and erythrocyte-stimulating agents. Conclusions: Integrated registry and pharmacy fill data provide a novel tool for pharmacoepidemiologic investigations of delivered post-transplant care. Transplant recipients with reduced renal function have increased requirements for pharmaceutical care of comorbidities. Causes of racial variation in medication fills warrant further investigation.