Differences in medication adherence between preemptive and post-dialysis young kidney transplant recipients.

BACKGROUND: The mechanisms underlying the superior graft survival associated with preemptive kidney transplantation, compared with transplantation following a period of dialysis, are unknown. We aimed to compare medication adherence between preemptively transplanted young kidney transplant recipients and those who received a transplant after an interval of dialysis. METHODS: This was a secondary analysis of the Teen Adherence in Kidney transplant Effectiveness of Intervention Trial (TAKE-IT), in which adherence was assessed with electronic monitoring over 15 months among 11-24-year-old transplant recipients. Adherence scores were calculated for each day as 0%, 50%, or 100% (intake of none, half, or all prescribed doses). We used ordinal logistic regression, with generalized estimating equations to account for repeated measures within each participant, to estimate the association between preemptive transplantation and adherence. The model was adjusted for sex, age at transplant, time since transplant, primary kidney disease, race, donor source, medication insurer, household income, and adherence intervention. RESULTS: There were 43 preemptive transplant recipients and 103 who had been treated with dialysis. The median adherence score was 85.1% (IQR 81.3-88.9) for those preemptively transplanted, and 80.0% (IQR 76.7-83.4) for those transplanted after dialysis. Preemptively transplanted recipients had significantly higher odds of adherence than those dialyzed before transplantation (adjusted OR 1.76 95% CI 1.21-2.55; p = 0.003). CONCLUSIONS: Preemptively transplanted patients showed significantly better adherence than those treated with dialysis before transplantation. This suggests that the superior outcomes observed among preemptive kidney transplant recipients may reflect selection of patients more likely to adhere to therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

Differences in Heart Graft Survival by Recipient Sex.

We aimed to characterize patterns of differences in heart graft failure rates by recipient sex, accounting for modifying effects of donor sex and recipient age. METHODS: We evaluated 69 246 first heart transplant recipients (1988-2019; Scientific Registry of Transplant Recipients). We used multivariable time-varying Cox models, considering recipient sex by donor sex by recipient age interaction and adjusting for potential confounders. Using the hazard ratio (HR) from the models and a fixed profile of recipient and donor characteristics, we also compared fitted absolute failure rates by recipient sex. RESULTS: Among recipients of male donors, female recipients of all ages had higher failure rates than males (0-12 y: HR 1.36 (95% confidence interval [CI], 1.03-1.81); 13-24 y: 1.43 [1.09-1.88]; 25-44 y: 1.22 [0.95-1.57]; ≥45 y: 1.16 [1.06-1.27]); differences were statistically significant in all age intervals except 25-44 y. When the donor was male, 13 to 24-y-olds showed the largest absolute difference in fitted absolute failure rates, with rates higher by 11.3 failures per 1000 person-y in female than male recipients. Among recipients of female donors, there were no statistically significant differences in graft failure rates between female and male heart recipients of any age. Although point estimates suggested higher failure rates in female than male recipients <25 y (0-12 y: HR 1.19 [95% CI, 0.85-1.66]; 13-24 y: 1.17 [0.84-1.63]), these were not statistically significant. CONCLUSIONS: Female recipients tended to have poorer outcomes than males, particularly at younger ages and when the donor was male, consistent with observations in kidney transplants.

Differences in Liver Graft Survival by Recipient Sex.

We aimed to characterize patterns of differences in liver graft failure rates by recipient sex, accounting for the modifying effects of donor sex and recipient age. METHODS: We evaluated 144 212 first deceased donor liver transplant recipients [1988-2019; Scientific Registry of Transplant Recipients (SRTR)]. We used multivariable time-varying Cox models, considering a recipient sex by donor sex by recipient age (0-12, 13-24, 25-44, ≥45 y) interaction. RESULTS: Among recipients of male donors, females <45 y had higher graft failure rates than males of the same age, but none of these differences were statistically significant [0-12 y: adjusted hazard ratio (aHR) 1.17 (0.98, 1.40); 13-24 y: aHR 1.18 (0.96, 1.46); 25-44 y: aHR 1.11 (0.96, 1.28)]; there was no material or statistically significant difference between female and male recipients ≥45 y [aHR 1.01 (0.97, 1.06)]. When the donor was female, recipients <45 y showed no statistically significant differences in graft outcomes by recipient sex [0-12 y: aHR 0.91 (0.74, 1.11); 13-24 y: aHR 0.98 (0.77, 1.25); 25-44 y: aHR 0.86 (0.73, 1.01)], whereas female recipients ≥45 y had significantly lower graft failure rates [aHR 0.85 (0.81, 0.89)] than males of the same age. CONCLUSIONS: Among recipients of female donors, female recipients ≥45 y had significantly better outcomes than males of the same age; there were no clear differences by recipient sex in younger recipients. When the donor was male, there was no material or statistically significant difference in graft failure rates between males and females ≥45 y; among younger recipients point estimates suggested higher failure rates in females than males recipients, but confidence intervals were wide making firm conclusions impossible. Larger studies combining multiple datasets are needed.