Understanding determinants of medication adherence and current adherence assessment practices in Australian haemodialysis patients

Medication nonadherence is a well-recognised problem in chronic diseases with a global prevalence rate estimated to be 50%. Determinants of nonadherence are multifactorial, although increasing complexity of disease and medication regimen contribute to nonadherence. End-stage kidney disease (ESKD) patients undergoing haemodialysis are prescribed complex regimens and are at high risk of medication nonadherence. Current clinical practice places significant emphasis on selecting medications that have been shown to improve patient outcomes, however little attention is paid to measuring and ensuring patient adherence to their prescribed treatments. Our understanding of factors contributing to medication nonadherence in patients undergoing haemodialysis is limited. This research sought to determine potential predictors of medication nonadherence, explore current practices and barriers to assessing adherence, and identify strategies to improve adherence assessment practices in clinical settings. The specific research objectives were to: ‚Äö summarise existing literature on medication nonadherence and identify factors associated with medication nonadherence in patients undergoing haemodialysis; ‚Äö investigate the prevalence pattern, and socio-demographic, clinical and psychosocial factors contributing to medication nonadherence in Australian haemodialysis patients, and ‚Äö identify current practices of assessing medication adherence in renal patients by health professionals, barriers to assessment, and strategies to improve adherence assessment practices in Australian dialysis centres. These research aims were investigated in four distinct studies. The first study summarised the existing literature on medication nonadherence using a systematic review. From the 44 relevant publications identified through the systematic review, the prevalence of medication nonadherence in patients undergoing haemodialysis varied between 12.5% and 98.6%. This wide variation occurred due to the heterogeneity in measures and definitions employed by the included studies. This inconsistency in the reporting of results did not allow us to conduct a more effective synthesis of results, such as meta-analysis, as part of the systematic review. However, through a narrative synthesis approach we identified a number of patient-, disease-, and medicationrelated factors contributing to nonadherence in patients undergoing haemodialysis. The second study was a prospective study of 53 adult (‚Äöv¢‚Ä¢ 18 years) patients undergoing haemodialysis, recruited from an outpatient dialysis centre in Hobart, Australia. More than half (56.6%, n = 30) of these patients were found to be nonadherent based on self-reports. Comparatively, nonadherence was much higher among the subset of patients (n = 33) analysed using pre-dialysis serum phosphate levels, as an objective measure (72.7%, n = 24). Increasing age was the only significant predictor of self-reported adherence (odds ratio (OR) 1.05; 95% CI 1.00‚Äö-1.11), whereas older age (OR 1.10; 95% CI 1.00‚Äö-1.21), higher level of comorbidity (OR 1.58; 95% CI 1.03‚Äö-2.42), and higher medication regimen complexity index (OR 1.14; 95% CI 1.02‚Äö-1.27) were independent predictors of objective adherence. The third study was a qualitative study aimed at exploring haemodialysis patients' perspectives on their medication-taking behaviour. Thirty patients undergoing haemodialysis from the aforementioned prospective study, completed one-on-one semi-structured interviews. The qualitative themes identified were mapped against WHO (World Health Organisation) determinants of adherence and comprised of patient-related (knowledge, awareness, attitude, self-efficacy, action control, and facilitation); health system/healthcare team-related (quality of interaction, and mistrust and collateral arrangements); therapy-related (physical characteristics of medicines, packaging, and side effects); condition-related (symptom severity); and social/economic factors (access to medicines, and relative affordability). Findings from the second and third study, led to the inception of the fourth study on healthcare professionals' perspectives on the issue of medication nonadherence in patients undergoing haemodialysis. As such, the fourth study consisted of crosssectional surveys and follow-up interviews with renal healthcare professionals, aimed at measuring their perceptions and practices of assessing adherence in clinical practice. A total of 113 renal nurses and 41 specialist renal pharmacists participated in this study. Attempts to engage renal doctors were unsuccessful despite trying various recruitment strategies. Renal nurses (83.2%, n = 89), relied heavily upon objective blood results to determine adherence, compared to pharmacists (57.1%, n = 16). Patient engagement via self-reported measures were rarely used by the pharmacists (27.6%, n = 8) compared to the nurses (55.1%, n = 59); this was mainly due to absence of a dedicated pharmacist to conduct such activities. Perceived barriers to assessing adherence by the renal professionals included: lack of time, administrative support, and patients' disinterest in discussing medication related issues. Survey participants were followed-up for a qualitative interview to expand on the survey findings and identify strategies to improve adherence assessment practices. Eighteen participants, comprising 12 nurses and six pharmacists, were interviewed. Three categories of barriers with seven underlying themes were identified: organisation-level (prioritisation of resources), professional-level (interplay between workload and available time, awareness and training deficits, and concerns around practicality/suitability of adherence tools), and patient-level (communication and assessment services, patient participation, and trust). Similarly, strategies that were identified to improve adherence assessment practices, included: formalisation of assessment process, integration of assessment process and tools into routine, and using multidisciplinary support. Despite the widespread prevalence of medication nonadherence among Australian haemodialysis patients, little attention has been given to ensuring patients adhere to their prescribed medicines. Communication and dialogue between patients and healthcare providers concerning medication-related issues are lacking within the dialysis settings. In order to improve this status quo, measuring nonadherence is vital. However, renal professionals placed too much emphasis on objective measures while assessing adherence; using such measures is subject to overlooking actual understanding of patient's medication-taking behaviour. As patient self-reported measures are important tools to supplement the objective measures, they should be promoted to healthcare providers so an open dialogue on medication nonadherence can be initiated. This may be a first step in a right direction in improving medication adherence in patients undergoing dialysis. In addition, current adherence assessment practices could be improved by formalising and integrating these practices into hospital policies and procedures. For example, by integrating adherence checklists into treatment sheets for routine assessments. Although easier said than done, having a dedicated and trained healthcare professional to measure adherence, is another key initiative that may improve medication adherence among dialysis patients. Finally, the importance of frequent discussion with patients to identify concerns they may have related to their medications cannot be overestimated.