Abstract
Background
Disease management initiatives to improve hypertension care, commonly conducted in managed care organizations today, focus on many determinants of blood pressure control including medication adherence. Empirical evidence supporting the association between adherence and improved control is lacking. This study was designed to evaluate the relationship between medication adherence and blood pressure control in a cohort of hypertensive managed care enrollees.
Methods
Prescription claims data for hypertensive adults continuously enrolled in a managed care plan throughout the calendar year 2000 were evaluated. A medication possession ratio (MPR, a measure of medication adherence) was calculated for each member, and patients with at least 50% adherence were eligible for the study. Medical records were then reviewed for a randomly selected cohort of those eligible members, stratified by calculated MPR. The association between degree of adherence and hypertension control was assessed.
Results
Blood pressure was controlled in 48.3% of enrolled patients (n = 708). There was no significant association between MPR and overall blood pressure control noted (prevalence ratio = 1.11; 95% CI 0.94, 1.31); however, adherence was associated with an increased likelihood of controlled diastolic blood pressure (prevalence ratio = 1.15; 95% CI 1.05, 1.27).
Conclusions
Hypertension is influenced by a variety of complex physiologic and behavior factors. When evaluated in isolation, overall blood pressure control does not appear to be independently associated with adherence. Interventions affecting multiple determinants of hypertension control should be given priority over those only designed to increase medication adherence when efforts to improve hypertension management are considered.
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Acknowledgements
Contributions from Barb Brancel Maley, RN; Marcel Grdinic, BS; Christopher Schuenke, PharmD; Colleen Smith, PharmD; Ryan Davis, PharmD; and Mel Yee, PharmD are acknowledged. We would also like to acknowledge Sara Hobbs-Kohrt and Heather Lueck for assistance with manuscript formatting.
Funding for this study was provided from an unrestricted educational grant to MaryAnn Steiner and Patrick Cory from Novartis Pharmaceuticals Inc. The funding source for this study was not involved in any aspect of the study.
Nilay Shah and Lawrence Fleming have no conflicts of interest directly relevant to the content of this study. Lee Vermeulen is a member of speakers’ bureaus and receives research funding from Amgen. He has also received funding from Novartis Pharmaceuticals.
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Shah, N.D., Steiner, M.E., Vermeulen, L.C. et al. The Role of Medication Adherence as a Determinant of Blood Pressure Control in a Managed Care Population. Dis-Manage-Health-Outcomes 15, 249–256 (2007). https://doi.org/10.2165/00115677-200715040-00006
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DOI: https://doi.org/10.2165/00115677-200715040-00006