Improving hypertension control in Australian general practice: a multi-method study using electronic health records

Background: Hypertension affects 6 million Australians and is the most significant contributor to cardiovascular morbidity and mortality. In addition to lifestyle adjustments, effective antihypertensive therapy is available to manage hypertension. Guidelines recommend treating patients according to their absolute cardiovascular disease (CVD) risk. However, adherence to guidelines and medication is poor.

Aim/Objectives: This study aims to inform the design of cost effective interventions for improving blood pressure (BP) control.

Methods: Methods include: (1) cross-sectional analyses of de-identified electronic medical records of 1.2 million patients attending 650 general practices across Australia between 2016-2018 (NPS MedicineInsight); (2) development of a costing model to estimate the cost of uncontrolled hypertension through increased absolute CVD risk and the effects of improving blood pressure control; and (3) a scoping review of interventions using behavioural economic concepts to improve medication adherence in patients with chronic conditions.

Findings: The prevalence of hypertension among adults was 39.8% (95% CI 38.7–40.9) and 54.9% (95% CI 54.2–55.5) were controlled (BP calculate CVD risk. Prescribing of antihypertensives was similar across all CVD risk categories (low risk=63.3% (95% CI: 61.9–64.8); moderate risk=61.8% (95% CI: 60.2–63.4); high risk=57.4% (95% CI: 55.4–59.4)). Cost analysis demonstrated a potential reduction of 18,307 CVD events over five years with an associated cost saving of $127 million with improved BP control. The review highlighted the importance of targeting non-adherent patients, understanding their reasons for non-adherence, and providing reminders and feedback to patients and physicians.

Implications: The findings from the scoping review provide a foundation for the design of interventions to improve adherence to BP medications, for which the findings on prevalence and costs provide the basis for early economic evaluations to inform the expected value of alternative intervention options.