title: Long-term persistence to mono and combination therapies with angiotensin converting enzymes and angiotensin II receptor blockers in Australia.
abstract: OBJECTIVE
  The purpose of this study was to compare the impact of initial antihypertensive therapy including angiotensin converting enzyme inhibitors (ACE) or angiotensin II receptor blockers (ARB) on long-term persistence to therapy.
  
  
  METHODS
  A retrospective cohort study using prescription claims data from the Australian Pharmaceutical Benefit Scheme (PBS). Kaplan-Meier analysis of prescription refills and cox proportional hazard models were used to compare the time on therapy (persistence) in people newly initiated to monotherapy or combination therapy including ACE or ARB, between April 2007 and March 2008. Differences in persistence to initial drug class or any antihypertensive therapy were reported at 4-year follow-up.
  
  
  RESULTS
  About 119,500 persons initiated ACE or ARB: 47 % initiated ACE monotherapy; 32 % ARB monotherapy; 13 % ACE combinations; and 8 % ARB combinations. Persistence (% on treatment at 4 years) to index therapy was lower in people starting ACE and ARB combinations compared to ACE or ARB monotherapies: ACE combination (12 %) versus ACE monotherapy (25 %) and ARB combinations (22 %) versus ARB monotherapy (35 %). Persistence was higher in those initiating fixed dose combinations (FDC) versus separate pill combinations of ACEs (19 vs. 10 %) and ARBs (25 vs. 14 %). Persistence at 4 years to any antihypertensive therapy was similar between initiators to ACE or ARB monotherapy (60 and 61 %, p = 0.08), ACE or ARB combinations (56 %, p = 0.99), and was slightly higher for separate pill combinations (57-59 %) versus FDC (55 %).
  
  
  CONCLUSIONS
  Choice of initial antihypertensive may have little impact on long-term persistence to therapy.
authors.affiliation: Quality Use of Medicines and Pharmacy Research Centre, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia.
authors.forename: Svetla
authors.initials: S
authors.lastname: Gadzhanova
authors.affiliation: Quality Use of Medicines and Pharmacy Research Centre, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia.
authors.forename: Elizabeth E
authors.initials: EE
authors.lastname: Roughead
authors.affiliation: Quality Use of Medicines and Pharmacy Research Centre, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia. louise@bartlet.com.au.|Department of Health, Commonwealth Government of Australia, Canberra, Australia. louise@bartlet.com.au.
authors.forename: Louise E
authors.identifier: http://orcid.org/0000-0002-0789-3855
authors.initials: LE
authors.lastname: Bartlett
mesh_terms: D000368:Aged; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001315:Australia; D057915:Drug Substitution / Q000706:statistics & numerical data; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D016903:Drug Monitoring
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents
keywords: Adherence; Angiotensin II receptor blocker (ARB); Angiotensin converting enzyme inhibitors (ACE); Antihypertensive; Fixed dose combinations (FDC); Persistence