Adherence to immunosuppressor medication in renal transplanted patients

Abstract

Non-adherence is a priority public health concern. Non-adherence means not taking medications, missing medications, taking too much, not taking enough, wrong timing, wrong dose and/or wrong pill, but may also refer to missing appointments, not booking appointments, not doing blood work, not returning calls and/or refusal to follow the treatment regimen. In renal transplantation, adherence to immunosuppressive medication is a fundamental requisite in order to preserve graft function, since non-adherence is one of the main causes for late acute rejection, incomplete recovery after rejection treatment, chronic graft dysfunction, graft loss, and death. Transplantation failure due to treatment non-adherence is economically, socially, ethically and morally unjustifiable. This is a very prevalent issue: in some studies, its incidence is as high as 70% of patients. The self-reported nonadherence levels found in certain studies, including those performed immediately after transplantation show the need for early and continued intervention after kidney transplantation in order to maximise adherence and consequently clinical outcomes. There is not a single method to assess non adherence, thus combining several measures increases diagnostic accuracy. Electronic monitoring with a microdevice that records each time a pill bottle is opened is considered the “gold standard” for measuring adherence, but self-report at a confidential interview was the best measure of adherence. Thus non-adherence risk can be effectively assessed using clinically available assessment tools. Medication Adherence Scale, Brief Medical Questionnaire, Immunosuppressant Therapy Adherence Scale, Immunosuppressant Therapy Barrier Scale, Long-Term Medication Behavior Self-Efficacy Scale and Simplified Medication Adherence Questionnaire are some of the self-reported questionnaires. There are multiple factors associated with non-adherence in immunosuppressant therapy: Younger patients (adolescent, especially), poor health coverage, poor social support, unmarried, no family, non-Caucasian, immigrant, lower income, lower socioeconomic class, greater parental distress and lower family cohesion; complex medical regimens, higher number of drugs, longer time after transplant, toxicity, side effects, poor tolerance to medication, higher number of physicians involved, poor provider-patient rapport; psychological (dependency, high levels of anxiety and hostility, poorer behavioral functioning and greater distress in children) and psychiatric (depression) illnesses, low self-efficacy with medicine intake, perception of immunosuppressive therapy as not been necessary to preserve kidney function, forgetfulness, rebelliousness, poor perception of health, poor satisfaction, low Health-related Quality of life, addictions, lack of coping strategies and avoidance behavior; patient morbidity: comorbidity, receiving a transplant from a live donor, retransplantation, and non-insulin-dependent diabetes. The most frequent strategies to promote medication-taking must focus on modifiable risk factors. Reasons for non-adherence are complex and diverse and any successful intervention aimed at improving adherence must be multidimensional. Although effective intervention strategies are needed to improve immunosuppressant therapy adherence, few intervention studies have been conducted in the adult renal transplant population. In this study, we perform an exhaustive review of the different strategies reported in the literature. A number of key reasons for non-adherence are also provided.

Keywords: Adherence, Transplantation outcomes, Renal transplantation, Immunosuppressive medication, Health-related quality of life

Core tip: Non-adherence is a priority public health concern. In renal transplantation, adherence is crucial to preserve graft functioning. Non-adherence rates of up to 70% of patients, including immediately after transplantation demonstrate the need for early and continued interventions after transplantation to maximise clinical outcomes. To increase the diagnostic accuracy of non-adherence, several measures must be combined. Multiple risk-factors exist. The strategies to foster medication-taking must focus on modifiable risk-factors and be of multidimensional nature. The strategies reported in the literature, some keys to understand non-adherence, and a few intervention studies are reviewed in this paper.