Epidemiology of cannabis use and associated outcomes among kidney transplant recipients: A meta-analysis.

OBJECTIVE: Cannabis is the most commonly used recreational drug in the United States, and transplant acceptability for cannabis using candidates varies among transplant centers. However, the prevalence and impact of cannabis use on outcomes of kidney transplant recipients remain unclear. This study aimed to summarize the prevalence and impact of cannabis use on outcomes after kidney transplantation. METHODS: A literature search was performed using Ovid MEDLINE, EMBASE, and The Cochrane Library Databases from inception until September 2019 to identify studies assessing the prevalence of cannabis use among kidney transplant recipients, and reported adverse outcomes after kidney transplantation. Effect estimates from the individual studies were obtained and combined utilizing random-effects, generic inverse variance method of DerSimonian-Laird. RESULTS: A total of four cohort studies with a total of 55 897 kidney transplant recipients were enrolled. Overall, the pooled estimated prevalence of cannabis use was 3.2% (95% CI 0.4%-20.5%). While the use of cannabis was not significantly associated with all-cause allograft failure (OR = 1.31, 95% CI 0.70-2.46) or mortality (OR = 1.52, 95% CI 0.59-3.92), the use of cannabis among kidney transplant recipients was significantly associated with increased death-censored graft failure with pooled OR of 1.72 (95% CI 1.13-2.60). CONCLUSIONS: The overall estimated prevalence of cannabis use among kidney transplant recipients is 3.2%. The use of cannabis is associated with increased death-censored graft failure, but not mortality after kidney transplantation.