title: Medication beliefs are associated with phosphate binder non-adherence in hyperphosphatemic haemodialysis patients.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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 necessity, 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Centre for Lifespan and Chronic Illness Research, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK.
authors.forename: Vari
authors.initials: V
authors.lastname: Wileman
authors.affiliation: Renal Unit Lister Hospital, Stevenage, UK.
authors.forename: Ken
authors.initials: K
authors.lastname: Farrington
authors.affiliation: Centre for Lifespan and Chronic Illness Research, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK.
authors.forename: David
authors.initials: D
authors.lastname: Wellsted
authors.affiliation: Southend University Hospital, Southend, UK.
authors.forename: Mike
authors.initials: M
authors.lastname: Almond
authors.affiliation: Center for Nephrology and Royal Free Hospital, University College London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Davenport
authors.affiliation: Institute of Psychiatry, King's College London, UK.
authors.forename: Joseph
authors.initials: J
authors.lastname: Chilcot
mesh_terms: D000328:Adult; D000368:Aged; D001294:Attitude to Health; D002614:Chelating Agents / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D003863:Depression / Q000523:psychology*; D005260:Female; D006801:Humans; D054559:Hyperphosphatemia / Q000188:drug therapy* / Q000523:psychology; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008297:Male; D055118:Medication Adherence / Q000523:psychology*; D008875:Middle Aged; D006435:Renal Dialysis; D011795:Surveys and Questionnaires
chemical_list: D002614:Chelating Agents
keywords: adherence; haemodialysis; hyperphosphatemia; medication beliefs; phosphate binders