Introduction:

Non-adherence in kidney transplants is diversely defined. Immunosuppression non-adherence (INA) is the most used
definition and has been associated with graft loss and acute rejection. But INA assesses only one fraction of adherence. Therefore, we
analyzed the association of a holistic non-adherence definition with transplant outcomes and compared its prediction performance with
other definitions.

Methods:

We retrospectively included 739 kidney recipients between 2019 and 2021. We evaluated holistic non-adherence (HNA),
suboptimal-immunosuppressor levels (SIL), appointment non-adherence (ANA), procedure non-adherence (PNA) and INA. The main
outcomes were graft loss, graft rejection, and mortality. A backward logistic regression was performed estimating adjusted and unadjusted odds ratio (OR) for each outcome. Finally, we compared the non-adherence definitions’ prediction for the main outcomes
using the area under the curve.

Results:

HNA was present in 28.7% of patients. Non-adherent patients had an adjusted OR of 2.66 (1.37–5.15) for mortality, 6.44 for
graft loss (2.71–16.6), and 2.28 (1.15–4.47) for graft rejection. INA and PNA presented a moderate discrimination for graft loss and
HNA and ANA mild-to-moderate discrimination for graft loss and death.

Conclusion:

Holistic non-adherence was associated with worst outcomes in kidney recipients and had a significant prediction
performance for graft loss and mortality

Keywords:

Kidney transplantation; patient adherence; mortality, graft survival; patient outcome assessment