Treatment gaps for hypertension management in rural Canadian patients with type 2 diabetes mellitus

Abstract

Background: There were a reported 2.2 million Canadians living with diabetes mellitus (DM) in 2002, of whom 1.98 million (90.0%) had type 2 DM. In addition, there are ∼60,000 new cases of type 2 DM diagnosed in Canada each year. However, the research shows that evidence and guidelines for management of hypertension in DM are not always translated into clinical practice. In rural areas, factors affecting implementation of recommendations and/or guidelines are less well understood, although some studies suggest that urban practices provide higher quality of care overall than rural areas. Objective: The goal of this study was to describe the patterns of medication use for hypertension for patients with type 2 DM in rural northern Alberta, Canada. We also tried to identify treatment gaps and opportunities for prescribing antihypertensives relative to the Canadian Diabetes Association's 1998 Clinical Practice Guidelines for the Management of Diabetes in Canada and the Canadian Hypertension Society Recommendations Working Group's 2003 Canadian Recommendations for the Management of Hypertension: Therapy. Methods: This study was conducted at the Institute of Health Economics and the University of Alberta (Edmonton, Alberta, Canada). We collected information from a cohort of patients aged ≥20 years with type 2 DM living in 2 adjacent rural regions of northern Alberta, Canada, at the time of enrollment in a diabetes care quality-improvement program as part of the Diabetes Outreach Van Enhancement (DOVE) study. Treatment gaps were determined by comparing antihypertensive pharmacotherapy with a blood pressure (BP) target of ≤130/≤85 mm Hg. We used multivariate regression analyses to determine the associations between sociodemographic and clinical characteristics and treatment gaps. Results: A total of 392 patients (229 women, 164 men; mean [SD] age, 62.3 [12.5] years) with type 2 DM were included in this analysis. Patients had a mean (SD) duration of diabetes of 8.3 (8.5) years. A total of 75.8% ( 297 392 ) of the study population had hypertension, and most ( 236 392 [60.2%]) were receiving some pharmacotherapy. Treatment gaps were present; 42.7% (n = 67) of patients not receiving pharmacotherapy for hypertension were above the established BP targets. For patients receiving monotherapy, 70% were not at BP targets. For patients receiving dual, triple, and ≥4 medications, 65%, 66%, and 46%, respectively, were not at BP targets. After controlling for systolic blood pressure, male sex (adjusted odds ratio [aOR], 2.17; 95% CI, 1.17–4.03), older age (aOR, 1.80 per decade; 95% CI, 1.51–2.09), lower self-reported physical health (aOR, 0.68; 95% CI, 0.41–0.96), higher body mass index (aOR, 1.05; 95% CI, 1.01–1.10), and past/current smoking (aOR, 1.95; 95% CI, 1.01–3.76) were all significantly associated with a lack of treatment for hypertension. Conclusions: Treatment maps in the management of hypertension exist in these rural Canadian patients with type 2 DM. Cardiovascular risk may be underestimated in these patients, particularly among younger patients and women, and those with multiple non-DM risk factors. These are patient subgroups that should be targeted as opportunities to improve hypertension management at the population level.