title: Clinical and economic impact of non-adherence to antidepressants in major depressive disorder: A systematic review.
abstract: BACKGROUND
  Medication non-adherence is one of the major challenges in treating patients with depression. This systematic review aims to determine the clinical and economic outcomes of non-adherence in depression.
  
  
  METHODS
  A systematic search was performed across the following databases: PubMed, EMBASE, DARE, CINAHL, PsycINFO, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews; from database inception to March 31, 2015. Studies must report on the association between adherence and outcomes, and English full texts needed to be available. The quality of each study was assessed using the Newcastle-Ottawa scale.
  
  
  RESULTS
  A total of 11 articles were included, with eight reporting on clinical outcomes, two reporting on economic outcomes, and one reporting on both. The majority of studies were retrospective cohort studies. The mean quality of all included studies was 7, with a range from 3 to 9. Results clearly indicate that patients who were non-adherent were more likely to experience increased risks of relapse and/or recurrence, emergency department visits, and hospitalization rates; increased severity of depression, and a decrease in response and remission rates. The worsening of clinical outcomes in patients who were non-adherent subsequently translated to an increase in healthcare utilization and charges.
  
  
  CONCLUSIONS
  No standardized adherence measurement tools were used, and few studies looked at the economic impact of non-adherence in depression.
  
  
  CONCLUSIONS
  There is a strong association between non-adherence to antidepressants and a worsening of patients' clinical and economic outcomes. Cost-effective interventions should be directed to this group of patients to improve medication adherence.
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang Malaysia.
authors.forename: Siew Ching
authors.initials: SC
authors.lastname: Ho
authors.affiliation: School of Pharmacy, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia.
authors.forename: Huey Yi
authors.initials: HY
authors.lastname: Chong
authors.affiliation: School of Pharmacy, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia; Center of Pharmaceutical Outcomes Research (CPOR), Department of Pharmacy Practice, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, Thailand; School of Pharmacy, University of Wisconsin, Madison, USA; School of Population Health, University of Queensland, Brisbane, Australia.
authors.forename: Nathorn
authors.initials: N
authors.lastname: Chaiyakunapruk
authors.affiliation: School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang Malaysia.
authors.forename: Balamurugan
authors.initials: B
authors.lastname: Tangiisuran
authors.affiliation: School of Pharmacy, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia. Electronic address: sabrina.anne@monash.edu.
authors.forename: Sabrina Anne
authors.initials: SA
authors.lastname: Jacob
mesh_terms: D000928:Antidepressive Agents / Q000627:therapeutic use*; D003865:Major Depressive Disorder / Q000188:drug therapy* / Q000191:economics; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D055118:Medication Adherence; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000928:Antidepressive Agents
keywords: Anti-depressive agents; Clinical; Depressive disorder; Economics; Medication adherence