Substance Use Among Potential Kidney Transplant Candidates and its Impact on Access to Kidney Transplantation; A Canadian Cohort Study

Evan Tang1, Aarushi Bansal1, Michelle Kwok1, Olusegun Famure1, S. Joseph Kim1, Daniel Z Buchman2,  Marta Novak3, Istvan Mucsi1

 

1Multiorgan Transplant Program, University Health Network, Toronto, Ontario, Canada

2 Department of Bioethics, University Health Network

3 Centre for Mental Health, University Health Network and Department of Psychiatry, University of Toronto, Toronto, Canada

Background

We assessed 1) the prevalence and associations of substance use among patients undergoing evaluation for kidney transplant (KT); 2) the association between substance use and access to KT waitlisting and KT.

Method

Single-centre cohort study of patients referred for KT evaluation between 2003 and 2012 (n = 1769). Substance use was identified from the social workers’ assessment and categorized by substance (Tobacco, Recreational, or Prescription drugs). The primary outcome was obtaining a final disposition (FD) (activated on the wait list, not activated on the wait list or cleared for living donor transplant). Secondary outcomes were obtaining a positive FD (activated on waitlist or cleared for living donor transplant) or KT. Univariable associations were explored using chi-square with covariable adjustment in multivariable logistic regression. The association between substance use and time from referral to outcome was examined using Cox proportional hazards models.

Results

Mean (SD) age was 49 (±14) years, 60% male, and 56% Caucasian. 17% of patients indicated substance use at the time of assessment (14% tobacco, 4% recreational drugs, and 1% prescription drugs). Substance use was more frequent among males (19% vs. 14%), single marital status (20% vs. 15%), Caucasians (21% vs. 14%), unemployed (54% vs. 41%), and patients with a history of non-adherence (25% vs. 15%) (p<0.01 for all comparisons) even after multivariable adjustment.

Patients with substance use had a lower cumulative probability for obtaining a FD within 2 years (59% vs 65%, log rank = 0.03). This association remained significant (HR 0.81, p = 0.014) after adjusting for sociodemographic variables and comorbidities. Patients with substance use were also less likely to obtain a positive FD within 2 years (adjusted HR 0.79, p = 0.010) and to receive KT (adjusted HR 0.77, p=0.006).

Conclusion

Younger age, male sex, Caucasian race, unemployment, and a history of non-adherence are associated with substance use in patients undergoing evaluation for KT. Substance use was associated with reduced access to KT. Further studies are needed to determine if substance use is associated with worse clinical outcomes after KT.

 

 

  • Non-organ specific: disparities to outcome & access to healthcare
  • Non-organ specific: economics, public policy, allocation, ethics