title: Understanding barriers to optimal medication management for those requiring long-term dialysis: rationale and design for an observational study, and a quantitative description of study variables and data.
abstract: BACKGROUND
  Rates of medication non-adherence in dialysis patients are high, and improving adherence is likely to improve outcomes. Few data are available regarding factors associated with medication adherence in dialysis patients, and these data are needed to inform effective intervention strategies.
  
  
  METHODS
  This is an observational cross-sectional study of a multi-ethnic dialysis cohort from New Zealand, with the main data collection tool being an interviewer-assisted survey. A total of 100 participants were randomly sampled from a single centre, with selection stratified by ethnicity and dialysis modality (facility versus home). The main outcome measure is self-reported medication adherence using the Morisky 8-Item Medication Adherence Scale (MMAS-8). Study data include demographic, clinical, social and psychometric characteristics, the latter being constructs of health literacy, medication knowledge, beliefs about medications, and illness perceptions. Psychometric constructs were assessed through the following survey instruments; health literacy screening questions, the Medication Knowledge Evaluation Tool (Okuyan et al.), the Beliefs about Medication Questionnaire (Horne et al.), the Brief Illness Perception Questionnaire (Broadbent et al.). Using the study data, reliability analysis for internal consistency is satisfactory for the scales evaluating health literacy, medication knowledge, and beliefs about medications, with Chronbach's α > 0.7 for all. Reliability analysis indicated poor internal consistency for scales relating to illness perceptions. MMAS-8 and all psychometric scores are normally distributed in the study data.
  
  
  CONCLUSIONS
  This study will provide important information on the factors involved in medication non-adherence in New Zealand dialysis patients. The resulting knowledge will inform long-term initiatives to reduce medication non-adherence in dialysis patients, and help ensure that they are addressing appropriate and evidence based targets for intervention.
authors.affiliation: School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand. t.aspden@auckland.ac.nz.
authors.forename: Trudi
authors.initials: T
authors.lastname: Aspden
authors.affiliation: School of Medicine, University of Queensland, 288 Herston Road, Brisbane, 4006, Australia. martin.wolley@gmail.com.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Wolley
authors.affiliation: Department of Renal Medicine, Counties Manukau District Health Board, Hospital Road, Otahuhu, Auckland, 1640, New Zealand. maggiema.aut@gmail.com.
authors.forename: Tian M
authors.initials: TM
authors.lastname: Ma
authors.affiliation: Marketing Department, Faculty of Business, Auckland University of Technology, 46 Wakefield St, Auckland, 1010, New Zealand. erajah@aut.ac.nz.
authors.forename: Edwin
authors.initials: E
authors.lastname: Rajah
authors.affiliation: Formerly of the School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand. samlouisecurd@gmail.com.
authors.forename: Samantha
authors.initials: S
authors.lastname: Curd
authors.affiliation: Formerly of the School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand. dharni_k91@hotmail.com.
authors.forename: Dharni
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Formerly of the School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand. sophia.lee2404@gmail.com.
authors.forename: Sophia
authors.initials: S
authors.lastname: Lee
authors.affiliation: Formerly of the School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand. krenny_p@hotmail.com.
authors.forename: Krenare
authors.initials: K
authors.lastname: Pireva
authors.affiliation: Formerly of the School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand. olita_85@hotmail.com.
authors.forename: Olita
authors.initials: O
authors.lastname: Taule'alo
authors.affiliation: Formerly of the School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand. pjtiavale@gmail.com.
authors.forename: Porsche
authors.initials: P
authors.lastname: Tiavale
authors.affiliation: Pharmacy Services, Counties Manukau District Health Board, Hospital Road, Otahuhu, Auckland, 1640, New Zealand. angela.kam@middlemore.co.nz.
authors.forename: Angela L
authors.initials: AL
authors.lastname: Kam
authors.affiliation: Department of Renal Medicine, Counties Manukau District Health Board, Hospital Road, Otahuhu, Auckland, 1640, New Zealand. junssuh@gmail.com.
authors.forename: Jun S
authors.initials: JS
authors.lastname: Suh
authors.affiliation: School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand. julia.kennedy@auckland.ac.nz.
authors.forename: Julia
authors.initials: J
authors.lastname: Kennedy
authors.affiliation: School of Medicine, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Rd, Auckland, 1142, New Zealand. mrmarsh@woosh.co.nz.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Marshall
mesh_terms: D015331:Cohort Studies; D003430:Cross-Sectional Studies; D007722:Health Knowledge, Attitudes, Practice; D057220:Health Literacy; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy*; D055118:Medication Adherence; D009520:New Zealand; D011594:Psychometrics; D006435:Renal Dialysis; D057566:Self Report; D011795:Surveys and Questionnaires; D044465:White People