Abstract
BACKGROUND: Centers for Disease Control and Prevention guidelines recommend caution in prescribing opioids for chronic pain. The characteristics of opioid prescription (OpRx) among kidney transplant (KTx) recipients have not been described in a national population. METHODS: We assessed OpRx prevalence among prevalent KTx recipients, and associated duration (long-term, defined as ≥90 days in a year) and dosing (in morphine milligram equivalents per day of <50, 50-89, and ≥90) with outcomes, death and graft loss, among incident KTx recipients using 2006-2010 US Renal Data System files, including Medicare Part D for medication ascertainment. Cox models controlled for recipient factors. RESULTS: Of 36,486 KTx recipients in the 2010 prevalent cohort, approximately 14.6% had long-term OpRx. The strongest association with long-term OpRx after KTx was long-term OpRx before KTx (64%; adjusted odds ratio, 95% confidence interval, 95.2, 74.2-122.1). Incident KTx recipients with long-term OpRx had increased risk of mortality and graft loss compared with those without OpRx or short-term OpRx after KTx. This risk was highest among recipients with long-term OpRx doses of ≥90 morphine milligram equivalents or higher per day (adjusted hazard ratio, 95% confidence interval, 1.61, 1.24-2.10 for death, and 1.33, 1.05-1.67 for graft loss, respectively). CONCLUSIONS: In contrast to either no or short-term OpRx, long-term, and especially long-term high-dose OpRx, is associated with increased risk of death and graft loss in US KTx recipients. Causal relationships cannot be inferred, and OpRx may be an illness marker. Nevertheless, efforts to treat pain effectively in KTx recipients with less toxic interventions and decrease OpRx deserve consideration.