CLINICAL RESEARCH STUDY Antihypertensive Drug Persistence and Compliance Among Newly Treated Elderly Hypertensives in Ontario Oded Friedman, MD, a,c Finlay A. McAlister, MD, b Lingsong Yun, MD, c Norman R. C. Campbell, MD, d Karen Tu, MD, c,e,f for the Canadian Hypertension Education Program Outcomes Research Taskforce a Prosserman Centre for Health Research (Samuel Lunenfeld Research Institute, Mount Sinai Hospital), Toronto, Canada; b Division of General Internal Medicine, University of Alberta, Edmonton, Canada; c Institute For Clinical Evaluative Sciences, Toronto, Canada; d Departments of Medicine and Pharmacology and Therapeutics, Libin Cardiovascular Institute, University of Calgary, Canada; e University Health Network-Toronto Western Hospital Family Medicine Centre, Toronto, Canada; f Department of Family and Community Medicine, University of Toronto, Canada. ABSTRACT BACKGROUND: Poor medication-taking behaviors are important considerations in the management of hypertension. METHODS: We conducted a retrospective cohort study addressing antihypertensive drug persistence and compliance by linking 4 administrative databases and a province-wide clinical database in Ontario, Canada, to derive a cohort of elderly hypertensive patients, aged 66 years or more, who had received a new prescription for an antihypertensive agent between 1997 and 2005 to determine trends across years and associations with drug class and sociodemographic and other factors. RESULTS: Our cohort consisted of 207,473 patients (58.4% were women, mean age 74.2 years, 73.1% were comorbid-free), 41,236 of whom had diabetes. Persistence and compliance increased between 1997 and 2005 (all P .02) and were greater in those of higher socioeconomic status but lesser in urban residents (all P .0001). Persistence was lower in comorbid-free patients and greater in older patients, whereas compliance was lower in older patients and greater in women and comorbid-free patients (all P .0001). Significant differences between the drug classes emerged with initial prescriptions for all drug classes showing greater therapy and class persistence compared with diuretics (all P .0001). Angiotensin- converting enzyme inhibitors showed the best therapy persistence and compliance, and beta-blockers showed the worst compliance (all P .0001). CONCLUSION: Our data provide evidence of an overall improvement in antihypertensive drug compliance and persistence across years, as well as significant differences across drug classes and other patient-level factors. Awareness of such factors could translate into concerted efforts at optimizing medication-taking behaviors among newly diagnosed elderly hypertensive patients. © 2010 Elsevier Inc. All rights reserved. • The American Journal of Medicine (2010) 123, 173-181 KEYWORDS: Antihypertensive drug; Compliance; Hypertension; Persistence Poor medication-taking behaviors are particularly relevant for the management of chronic asymptomatic diseases, such as hypertension, in which no immediate physical symptoms result from such behaviors. 1 In the long-term, however, inadequate blood pressure control significantly increases the risks of target organ damage and death. Not surprisingly, economic analyses reveal considerable excess costs (up to one third of the total costs of the treatment of incident hypertensives) resulting from switching and discontinuation of initial therapy. 2 The basis for poor medication-taking behavior is likely multifactorial, stemming from factors at several levels. 1,3 Identification of factors that are associated with poor compliance/persistence could lead to concerted and focused efforts at optimizing medication-taking behaviors. In addi- Funding: Alberta Heritage Foundation for Medical Research. Conflict of Interest: None of the authors have any conflicts of interest associated with the work presented in this manuscript. Authorship: All authors had access to the data and played a role in writing this manuscript. Reprint requests should be addressed to Oded Friedman, MD, c/o Prosser- man Centre for Health Research (Samuel Lunenfeld Research Institute, Mount Sinai Hospital), 60 Murray Street, Toronto, Ontario, M5G1X5 Canada. E-mail address: ofriedman@hotmail.com 0002-9343/$ -see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.amjmed.2009.08.008