Enhancing Perceived Behavioral Control May Improve Post-Transplant Medication Adherence

A recent study published in Health Psychology and Behavioral Medicine is providing clinicians with an overview of psychological and behavioral factors related to immunosuppression medication (ISM) adherence among kidney transplant recipients (KTRs).1

The research highlighted psychological and behavioral variables that contributed to a hierarchy of adherence: total nonadherence, unintentional nonadherence, and intentional nonadherence. By combining perceived behavioral control (PBC) with common sense model (CSM), researchers were able to measure the factors that contributed to nonadherence and suggest further methods for intervention.

After kidney transplantation, it is 7 times as likely for graft failure to occur in nonadherent patients and missing as few as 5% of prescribed doses is associated with greater acute rejection and graft loss. A higher level of pill burden was recorded in patients with CKD, 80%, and highest in patients with a kidney transplant and those receiving dialysis2. Still, 57% of KTRs report some form of nonadherence to ISM, with unintentional non-adherence (54%) more common than intentional (14%).

“To develop effective interventions, it is necessary to distinguish between intentional non-adherence, where a decision is made not to take medication as prescribed, and unintentional non-adherence, which may be due to forgetting to take medication or not understanding the prescribed instructions,” Lyndsay Hughes, PhD, at the King’s College London and associate editor for the journal BMC Psychology, and colleagues wrote.1 “Intentional non-adherence is typically linked to perceptual barriers, whereas unintentional non-adherence is more often associated with practical barriers.”

The study included self-reported patient data from routine outpatient appointments at Guy’s Hospital Kidney Transplant Clinic in London between September 2022 and October 2023. Researchers provided KTRs with 20-40 minute iPad questionnaires assessing patient’s behaviors, beliefs, and medical information which was then extracted from electronic patient records by the team.

Researchers used a step regression approach to identify what factors predicted nonadherence, including clinical factors like pill burden, psychological factors such as depression and anxiety, and finally CSM and PBC beliefs and behaviors.

The study included 249 patients ≥ 18 years of age living with a kidney transplant, prescribed ISM, who read or spoke English. In total, 80% of patients were living with their first transplant, 69% of patients were prescribed triple immunosuppressive therapy, and 60% of patients received their transplant from a deceased donor.

Among the cohort, 170 (57%) participants were classified as nonadherent overall. Intentional nonadherence was reported by 41 (14%) patients, while the remaining, 161 (54%) reported unintentional nonadherence.

Upon analysis, greater levels of PBC (odds ratio [OR], 0.85; 95% CI, 0.77−0.94) were associated with decreased odds of intentional nonadherence, while no CSM variables reached statistical significance. Findings also suggested greater levels of depression and anxiety increase odds of total nonadherence, intentional, and unintentional.

Investigators additionally pointed out that, contrary to their hypothesis, higher pill burden reduced odds of both intentional and total nonadherence. As understanding progresses on predictive variables for ISM adherence in KTRS, enhancing PBC around medication is a clear goal.

Investigators conclude, “This was the first study to examine both graft-specific as well as broader CKD perceptions, in conjunction with beliefs about ISM, and PBC around taking ISM in relation to total, intentional and unintentional non-adherence in KTRs. Results identified unique psychological correlates for intentional and unintentional non-adherence, highlighting the distinction and the need for targeted interventions to address medication non-adherence in this patient cohort.”1

References

1. Heape R, Cronin, AJ, Hughes L. Understanding immunosuppression medication adherence in kidney transplant recipients: a cross-sectional exploration of the role of illness perceptions, medication beliefs and perceived behavioural control. Health Psychology and Behavioral Medicine, 13(1). https://doi.org/10.1080/21642850.2025.2562857

2. Oosting IJ, Colombijn JMT, Kaasenbrood L, et al. Polypharmacy in Patients with CKD: A Systematic Review and Meta-Analysis. Kidney360. https://doi.org/10.34067/KID.0000000000000447