Quantifying prognostic impact of prescription opioid use before kidney transplantation through linked registry and pharmaceutical claims data

Background. Limited data are available on the outcome implications of prescription narcotic use before kidney transplantation.

Methods. We examined a novel database wherein national transplant registry identifiers for kidney transplant recipients were linked to records from a large U.S. pharmaceutical claims clearinghouse (2005-2010). We selected recipients with 1 year of captured pretransplant pharmaceutical fill records (N=31,197). Opioid analgesic fills in the year before transplantation were normalized to morphine equivalents (ME) and expressed as mg/kg exposures. Adjusted associations of ME level with posttransplant graft and patient survival (adjusted hazards ratio, aHR) were quantified by multivariate Cox regression.

Results. Among the 29% of the sample who filled opioid prescriptions in the year before transplantation, the 25th, 50th, and 75th percentiles of annual ME were 1.8, 5.5, and 23.7 mg/kg, respectively. Three-year graft survival was 88.0% and 84.4% in live donor recipients with upper quartiles of ME use, compared with 92.0% among those who did not receive prescription narcotics (P<0.0001). Adjusted risks of posttransplant death and all-cause graft loss in live donor recipients with the highest quartile of narcotic use were 2.3 times (aHR, 2.27; 95% confidence interval, 1.66-3.10) and 1.8 times (aHR, 1.75; 95% confidence interval, 1.37-2.26), respectively, that of narcotic nonusers. Graded associations of pretransplant opioid exposure level with death and graft loss after deceased donor transplantation were also observed.

Conclusions. Although associations may in part reflect underlying conditions or behaviors, high levels of prescription opioid use before kidney transplantation predict increased risk of posttransplant death and graft loss.