title: Prospective analysis of the medicine possession ratio of antidepressants in the private health sector of South Africa, 2006 - 2011.
abstract: BACKGROUND
  Major depressive disorder (MDD) is a disabling mental illness with high morbidity and mortality rates. Inadequate treatment efficacy, unfavourable side-effect profiles and consequent shortfalls in compliance are major stumbling blocks in its treatment. Non-compliance data in low- to middle-income countries are lacking.
  
  
  OBJECTIVE
  To investigate the prevalence of antidepressant (AD) non-compliance in the private healthcare sector of South Africa (SA).
  
  
  METHODS
  We conducted a prospective cohort study analysing AD medicine claims (N=35 175) for 14 135 patients, obtained from a nationally representative pharmaceutical benefit management company, over a 6-year study period (1 January 2006 - 31 December 2011). The medicine possession ratio (MPR) was used as a proxy to determine compliance with AD medication. Only patients &gt;18 years of age whose treatment had been initiated by a psychiatrist following an appropriate International Classification of Diseases (10th edition) (ICD-10) diagnosis of a mood disorder were included. A patient was considered compliant if the MPR was between ≥80% and ≤110% over a &gt;4-month treatment period.
  
  
  RESULTS
  After the first 4 months, only 34% of patients were compliant. A statistically significant association was found between active ingredient consumed and compliance (p&lt;0.0001). Only 26.2% of patients who received amitriptyline-containing products were compliant, compared with 38.8% and 38.7% for venlafaxine and duloxetine, respectively.
  
  
  CONCLUSIONS
  Compliance data collected from pharmacy claims provide a workable estimate of the broader clinical scenario they represent. Although differences between classes of AD were evident, non-compliance was found to be high in the private healthcare environment of SA, comparable with global trends.
authors.affiliation: Medicine Usage in South Africa (MUSA), School of Pharmacy, Faculty of Health Sciences, North-West University, Potchefstroom, North West, South Africa. naude.slabbert@nwu.ac.za.
authors.forename: Francois Naude
authors.initials: FN
authors.lastname: Slabbert
authors.forename: Brian H
authors.initials: BH
authors.lastname: Harvey
authors.forename: Christiaan Beyers
authors.initials: CB
authors.lastname: Brink
authors.forename: Martha Susanne
authors.initials: MS
authors.lastname: Lubbe