title: Is cost-related non-collection of prescriptions associated with a reduction in health? Findings from a large-scale longitudinal study of New Zealand adults.
abstract: OBJECTIVE
  To investigate whether cost-related non-collection of prescription medication is associated with a decline in health.
  
  
  METHODS
  New Zealand Survey of Family, Income and Employment (SoFIE)-Health.
  
  
  METHODS
  Data from 17 363 participants with at least two observations in three waves (2004-2005, 2006-2007, 2008-2009) of a panel study were analysed using fixed effects regression modelling.
  
  
  METHODS
  Self-rated health (SRH), physical health (PCS) and mental health scores (MCS) were the health measures used in this study.
  
  
  RESULTS
  After adjusting for time-varying confounders, non-collection of prescription items was associated with a 0.11 (95% CI 0.07 to 0.15) unit worsening in SRH, a 1.00 (95% CI 0.61 to 1.40) unit decline in PCS and a 1.69 (95% CI 1.19 to 2.18) unit decline in MCS. The interaction of the main exposure with gender was significant for SRH and MCS. Non-collection of prescription items was associated with a decline in SRH of 0.18 (95% CI 0.11 to 0.25) units for males and 0.08 (95% CI 0.03 to 0.13) units for females, and a decrease in MCS of 2.55 (95% CI 1.67 to 3.42) and 1.29 (95% CI 0.70 to 1.89) units for males and females, respectively. The interaction of the main exposure with age was significant for SRH. For respondents aged 15-24 and 25-64 years, non-collection of prescription items was associated with a decline in SRH of 0.12 (95% CI 0.03 to 0.21) and 0.12 (95% CI 0.07 to 0.17) units, respectively, but for respondents aged 65 years and over, non-collection of prescription items had no significant effect on SRH.
  
  
  CONCLUSIONS
  Our results show that those who do not collect prescription medications because of cost have an increased risk of a subsequent decline in health.
authors.affiliation: Alfred Deakin Institute for Citizenship & Globalisation, Deakin University Waterfront Campus, Geelong, Victoria, Australia.
authors.forename: Santosh
authors.initials: S
authors.lastname: Jatrana
authors.affiliation: Department of Public Health, Wellington School of Medicine and Health Sciences, University of Otago, Wellington, New Zealand.
authors.forename: Ken
authors.initials: K
authors.lastname: Richardson
authors.affiliation: School of Pharmacy, University of Otago, Dunedin, New Zealand.
authors.forename: Pauline
authors.initials: P
authors.lastname: Norris
authors.affiliation: University of Otago, Dunedin, New Zealand.
authors.forename: Peter
authors.initials: P
authors.lastname: Crampton
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D009520:New Zealand; D055553:Prescription Drugs / Q000191:economics*; D011306:Prescription Fees; D012737:Sex Factors; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D055553:Prescription Drugs
keywords: EPIDEMIOLOGY; PRIMARY CARE; PUBLIC HEALTH