Cannabis is categorized as an illicit drug in most US states, but legalization for medical indications is increasing. Policies and guidance on cannabis use in transplant patients remain controversial.
We examined a database linking national kidney transplant records (n = 52 689) with Medicare claims to identify diagnoses of cannabis dependence or abuse (CDOA) and associations [adjusted hazard ratio (aHR) with 95% upper and lower confidence limits (CLs)] with graft, patient, and other clinical outcomes.
CDOA was diagnosed in only 0.5% (n = 254) and 0.3% (n = 163) of kidney transplant recipients in the years before and after transplant, respectively. Patients with pretransplant CDOA were more likely to be 19 to 30 years of age and of black race, and less likely to be obese, college-educated, and employed. After multivariate and propensity adjustment, CDOA in the year before transplant was not associated with death or graft failure in the year after transplant, but was associated with posttransplant psychosocial problems such as alcohol abuse, other drug abuse, noncompliance, schizophrenia, and depression. Furthermore, CDOA in the first year posttransplant was associated with an approximately 2-fold increased risk of death-censored graft failure (aHR, 2.29; 95% CL, 1.59–3.32), all-cause graft loss (aHR, 2.09; 95% CL, 1.50–2.91), and death (aHR, 1.79; 95% CL, 1.06–3.04) in the subsequent 2 years. Posttransplant CDOA was also associated with cardiovascular, pulmonary, and psychosocial problems, and with events such as accidents and fractures.
Although associations likely, in part, reflect associated conditions or behaviors, clinical diagnosis of CDOA in the year after transplant appears to have prognostic implications for allograft and patient outcomes. Recipients with posttransplant CDOA warrant focused monitoring and support.
1 Division of Nephrology, Washington University School of Medicine, St. Louis, MO.
2 Division of Nephrology, Saint Louis University School of Medicine, St. Louis, MO.
3 Division of Nephrology, University of Alberta, Edmonton, AB, Canada.
4 Division of Nephrology, Department of Medicine, University of Michigan, Ann Arbor, MI.
5 Center for Abdominal Transplantation, Saint Louis University, St. Louis, MO.
6 Division of Transplantation, Department of Surgery, Lahey Clinic, Burlington, MA.
7 Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
8 Center for Transplantation, Johns Hopkins School of Medicine, Baltimore, MD.
9 School of Pharmacy, Southern Illinois University, Edwardsville, MO.
10 Hennepin County Medical Center, Minneapolis, MN.
Received 23 July 2018. Revision received 1 December 2018.
Accepted 5 December 2018.
This work was conducted under the auspices of the Minneapolis Medical Research Foundation, contractor for the Scientific Registry of Transplant Recipients (SRTR), as a deliverable under contract HHSH250201000018C (US Department of Health and Human Services, Health Resources and Services Administration, Healthcare Systems Bureau, Division of Transplantation). As a US Government-sponsored work, there are no restrictions on its use. The interpretation and reporting of these data are the responsibility of the author(s) and in no way should be seen as an official policy of or interpretation by the SRTR or the US Government. This work was supported by a grant from the National Institutes of Health (NIH)/National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) R01-DK096008. N.N.L. was supported by the KRESCENT New Investigator Award.
Previous Presentation: This study was presented in part as an oral abstract at the American Transplant Congress, June 4, 2018; Seattle, WA.
The authors declare no conflicts of interest.
T.A., F.M.K., N.N.L., S.K., A.S.N., H.R., R.O., R.D., and B.L.K. participated in the study design, interpretation, and writing of the paper. M.A.S. and K.L.L. participated in study design, acquisition of data and regulatory approvals, data analysis, and writing of the paper. H.X. participated in data analysis and manuscript preparation. D.A.A., V.R.D., D.C.B., and D.L.S. participated in study design, interpretation, and writing of the paper. Support provided to the authors’ institutions by the NIH/NIDDK.
Supplemental digital content (SDC) is available for this article. Direct URL citations appear in the printed text, and links to the digital files are provided in the HTML text of this article on the journal’s Web site (www.transplantjournal.com).
Correspondence: Krista L. Lentine, MD, PhD, Saint Louis University Transplant Center, 1402 S. Grand Blvd., St. Louis, MO 63104, USA. (firstname.lastname@example.org).