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.