Impact of a pharmaceutical care program on liver transplant patients' compliance with immunosuppressive medication: a prospective, randomized, controlled trial using electronic monitoring

Immunosuppressant nonadherence in heart, liver, and lung transplant patients: associations with medication beliefs and illness perceptions

BACKGROUND

Nonadherence to immunosuppressant medication is a significant problem among solid organ transplant recipients. Previous research suggests that patients' perceptions about their medications may be a better predictor of nonadherence than demographic factors. This study aimed to further investigate the role of patients' perceptions about their transplant and medication beliefs in nonadherence.

METHODS

This was a cross-sectional observational study. Participants were 87 heart, 46 lung, and 193 liver transplant patients. All surviving heart, lung, and liver transplant patients from Auckland City Hospital and Greenlane Hospital older than 16 years who had received their transplant at least 3 months before study commencement were mailed questionnaires. Standardized self-report measures were used to assess illness perceptions, medication beliefs, and adherence.

RESULTS

Nonadherent patients had lower perceptions about the necessity of medication, weaker beliefs that medication could prevent rejection, and higher concerns about its harms, than adherers. Nonadherers perceived that their transplant and immunosuppressant medication caused more symptoms and were more distressed about symptoms than adherers; they understood their transplant less, perceived their transplant had a larger impact on their lives, affected them more emotionally, and caused greater concern, than patients who were more adherent. A regression model that included these perceptions and demographic variables correctly classified 71% of patients as adherent or nonadherent.

CONCLUSIONS

The perceptions that patients hold about their transplant and medications are associated with adherence to immunosuppressant medications. Future research could investigate whether a psychologic intervention could change patients' perceptions to improve adherence.

Adherence to immunosuppression in adult lung transplant recipients: prevalence and risk factors

BACKGROUND

Adherence to medication is a favourable with regard to survival after kidney, heart and liver transplantation. Little is known about adherence to medication in lung transplant recipients. To determine the prevalence of adherence and identify risk factors of non-adherence (NA) we evaluated adherence to tacrolimus in adult lung transplant recipients who were at least 1 year after transplantation.

METHODS

Tacrolimus intake was prospectively monitored using the Medication Event Monitoring System (MEMS). Recipients qualified as adherent if a timing-adherence score of ≥ 80% was reached. Patients' characteristics and possible risk factors for NA were collected using the Karnofsky Performance Index, Self-Care Agency ASA Scale, State-Trait Anxiety Inventory, Zung Self-Rating Depression Scale, and the Long-Term Medication Behavior Self-Efficacy Scale.

RESULTS

Ninety-one recipients used MEMS for a median of 95 days (range 50 to 124 days) and were included. They showed a median timing-adherence score of 98.1% (range 31.2% to 100%). A timing-adherence score of ≥ 80% was seen in 92.3% of the recipients. Multiple logistic regression showed an association of lower timing-adherence scores with younger age and lower ability of self-care.

CONCLUSIONS

Adherence to immunosuppressive therapy was very high in lung transplant recipients. Only 7.7% of the recipients were non-adherent. Younger recipients and recipients with lower ability of self-care appeared to be at risk for NA. Follow-up of clinical data is needed to determine whether NA is associated with poorer outcome, specifically bronchiolitis obliterans syndrome.

Adherence in liver transplant recipients

Adherence to a medical regimen has been defined as the extent to which a patient's behavior coincides with clinical prescriptions. In liver transplant patients, adherence to immunosuppressive therapy and to medical indications in general is crucial for short- and long-term outcomes. Nonadherence to immunosuppression carries a risk of graft rejection and potential graft loss, whereas nonadherence to general medical indications (eg, avoiding alcohol intake and smoking after transplantation) may be associated with other complications such as de novo tumors and increasing health care costs. Among adult liver transplant patients, the rate of nonadherence to immunosuppressive drugs ranges from 15% to 40%, whereas the rate of nonadherence to clinical appointments ranges from 3% to 47%. The wide range of reported rates is due to different definitions of the term nonadherence and the variety of methods used to measure adherence in the medical literature. Nonadherence seems to be nearly 4 times higher in pediatric and adolescent patients versus adult transplant recipients. Several nonadherence risk factors, such as high medication costs, psychiatric disorders, the conviction that the medication is harmful, and side effects of immunosuppressive therapy, have been described among adult liver transplant patients. The risk factors for nonadherence in pediatric and adolescent liver transplant patients are psychological distress, the functional status of their families, and the impact of immunosuppressive side effects on their physical appearance. A single approach to promoting adherence to general medical prescriptions has been proved to be ineffectual, so a multidisciplinary strategy should be adopted to achieve significant improvements in this field. The aim of this review is to analyze the published literature on adherence in liver transplant patients with a particular focus on the reported prevalence and the identified risk factors. Patients have been split into 2 age groups (adults and children/adolescents) because the scale of the problem and the potential risk factors differ in the 2 groups.