Vari Wileman

Objective: Haemodialysis patients are at risk of serious health complications; yet, treatment non-adherence remains high. Warnings about health risks associated with non-adherence may trigger defensive reactions. We studied whether an intervention based on self-affirmation theory reduced resistance to health-risk information and improved fluid treatment adherence. Design: In a cluster randomised controlled trial, 91 patients either self-affirmed or completed a matched control task before reading about the health-risks associated with inadequate fluid control. Outcome measures: Patients’ perceptions of the health-risk information, intention and self-efficacy to control fluid were assessed immediately after presentation of health-risk information. Interdialytic weight gain (IDWG), excess fluid removed during haemodialysis, is a clinical measure of fluid treatment adherence. IDWG data were collected up to 12 months post-intervention. Results: Self-affirmed patients had significantly reduced IDWG levels over 12 months. However, contrary to predictions derived from self-affirmation theory, self-affirmed participants and controls did not differ in their evaluation of the health-risk information, intention to control fluid or self-efficacy. Conclusion: A low-cost, high-reach health intervention based on self-affirmation theory was shown to reduce IDWG over a 12-month period, but the mechanism by which this apparent behaviour change occurred is uncertain. Further work is still required to identify mediators of the observed effects.

Objectives: Patients with end‐stage kidney disease receiving haemodialysis ( HD ) are at risk of cardiovascular disease and bone disorders related to high levels of serum phosphate. We studied the association between medication beliefs and depressive symptoms, with non‐adherence to phosphate binding medication in a group of HD patients at risk of complications due to hyperphosphatemia. Design: Cross‐sectional design. Methods: Baseline data from 112 patients participating in a randomized controlled trial, evaluating an adherence intervention, are presented. All patients had serum phosphate levels >1.6 mmol/l at baseline. Adherence was measured by (1) serum phosphate and (2) Medication Adherence Report Scales ( MARS ). Beliefs about Medicines ( BMQ ) and depressive symptoms ( PHQ ‐9) were also evaluated. Results: Beliefs about Medicines Questionnaire n ecessity , but not concerns, beliefs were found to correlate with serum phosphate ( r  =   −.23, p <  .05) and self‐reported adherence ( r  =   .35, p  <   .01). In regression models, controlling for demographic, clinical and psychological variables, necessity beliefs explained the variance of serum phosphate (β   =   −.22, p  =   .01) and self‐reported adherence (β   =   .30, p  ≤ .01). Both BMQ concerns and depressive symptoms were not related to non‐adherence. Conclusion: Patients' beliefs about the necessity of their prescribed phosphate binding medications explain variation in non‐adherence levels, measured both subjective and objectively. Dialysis patient's medication beliefs are potentially modifiable targets for future interventions. Statement of contribution: What is already known on this subject? Haemodialysis patients are at risk of cardiovascular disease and bone disorders related to high levels of serum phosphate, yet adherence to phosphate binders remains suboptimal. Treatment beliefs have been shown to predict adherence to phosphate binders. What does this study add? In patients who are at risk of complications due to high phosphate levels, beliefs regarding the necessity of phosphate binders are associated with treatment non‐adherence as measured by a physiological proxy (serum phosphate levels) and self‐report. Depression does not appear to be related to phosphate binder non‐adherence.

Hemodialysis patients are at risk of serious health complications, yet treatment non-adherence remains high. Warnings about health risks associated with non-adherence may trigger defensive reactions. We studied whether an intervention based on self-affirmation theory (Steele 1988) reduced patients’ resistance to health-risk information and improved adherence. One hundred twelve patients either self-affirmed or completed a matched control task before reading about the risks associated with a lack of phosphate control. Serum phosphate was collected from baseline up to 12 months. Self-affirmed patients had significantly reduced serum phosphate levels at 1 and 12 months. However, contrary to the predictions derived from self-affirmation theory, self-affirmed participants and controls did not differ in their evaluation of the health-risk information, behavioural intention or self-efficacy. A low-cost, high-reach health intervention based on self-affirmation theory was shown to reduce serum phosphate over a 12 month period. Further work is required to identify mediators of the observed effects.

Objective: Patients with end-stage renal disease (ESRD) receiving haemodialysis are at risk of cardiovascular disease and bone disorders related to high levels of serum phosphate (PO4). Phosphate binders are an important treatment; however, non-adherence remains a significant issue. This study investigates whether patients’ beliefs about medicines predict intentional non-adherence to phosphate binders. Method: This was a cross-sectional study of ESRD patients (n = 76). Non-adherence was measured in two ways: (1) the self-report Medication Adherence Questionnaire (MAQ) and (2) 3-month average level of serum phosphate. The Beliefs about Medicines questionnaire was used to assess general and specific beliefs towards phosphate medicines. Results: Eleven (14.5% of 76) patients reported being intentionally non-adherent to phosphate binders. Patients’ beliefs that phosphate binders were less necessary were significantly associated with intentional self-reported non- adherence. Furthermore, patients with greater concerns about phosphate binders had higher serum phosphate levels. Conclusion: Assessing patient beliefs about medicines is a reliable indicator of intentional non-adherence to treatment with phosphate binders. These findings may help in identifying ways in which adherence rates to phosphate binders can be improved.