Implementing Improved Blood Pressure Measurement in General Practice: A Multisite Implementation Trial Using Automated Office Blood Pressure (AOBP)

N/ANot Yet RecruitingNCT07822022

Menzies Institute for Medical Research6,000 enrolled

Overview

The goal of this clinical trial is to evaluate whether implementation of guideline-recommended Automated Office Blood Pressure (AOBP) measurement in Australian general practice clinics improves hypertension control among adults aged 18 years and older who are eligible for blood pressure assessment as part of routine clinical care. The study will also evaluate the implementation, sustainability, and health economic impact of AOBP in real-world primary care settings. The main questions it aims to answer are: * Does implementation of AOBP increase the proportion of patients with treated and controlled hypertension compared with the pre-implementation period? * Can AOBP be successfully adopted, implemented, integrated into routine general practice workflows, and maintained over time? Researchers will compare outcomes following implementation of AOBP with routinely collected clinical data from the period before implementation. Participants will: * Provide informed consent and have their AOBP measurements performed during routine general practice visits. * Consent to the collection of AOBP measurement and relevant clinical information from their medical records for study evaluation. * Continue to receive usual clinical care from their general practitioner. General practice staff will receive AOBP training, perform AOBP measurements, and participate in implementation evaluation activities.

Hypertension is the most common condition managed in general practice and remains one of the leading modifiable risk factors for cardiovascular disease (CVD). Accurate blood pressure (BP) measurement is fundamental to hypertension diagnosis and management; however, guideline-recommended clinic BP measurement procedures are often difficult to implement in routine practice because of time, staffing, and workflow constraints. General practitioners have reported that guideline-recommended BP measurement approaches are frequently impractical in routine clinical care, which may contribute to reduced confidence in clinic BP readings and therapeutic inertia. Automated Office Blood Pressure (AOBP) measurement is a standardized approach to clinic BP assessment designed to reduce observer and procedural bias. The method incorporates an automated rest period followed by repeated automated measurements obtained while the patient remains seated, quiet, and undisturbed. AOBP values correlate closely with out-of-office BP measurement methods and, in 2025, AOBP was endorsed by Hypertension Australia and the National Hypertension Taskforce as the recommended standard for clinic BP measurement in Australia. AOBP is typically performed by a trained staff member before the patient sees the general practitioner, in a quiet area outside the consultation room. This approach is intended to provide a more standardized BP assessment, reduce demands on consultation time, and support clinical decision-making through more reliable BP information while maintaining existing clinical care pathways and clinician responsibility for diagnosis, treatment, follow-up, and referral decisions. Despite guideline endorsement and supporting evidence, AOBP has not been routinely implemented in Australian general practice. Barriers to implementation are predominantly structural rather than clinical and include limited access to validated equipment, staff training requirements, workflow integration challenges, and the absence of coordinated implementation support. The study was informed by extensive co-design work involving general practitioners, practice staff, partner organisations, and community members. Previous pilot implementation work demonstrated that AOBP could be integrated into general practice workflows and was considered feasible, acceptable, and adaptable across diverse practice settings when supported by appropriate training, workflow integration, and governance arrangements. GPs participating in pilot implementation work reported increased trust in BP readings and greater confidence in hypertension management. This study is a pragmatic, multisite, hybrid type 2 implementation-effectiveness trial using a non-randomised pre-post design. Approximately 40 Australian general practice clinics will participate in the study, with implementation occurring within each clinic over a 12-month period followed by a 6-month maintenance phase. The study has been designed to evaluate implementation of Automated Office Blood Pressure (AOBP) measurement within routine primary care settings and examine factors influencing implementation and sustainability in general practice. The hybrid type 2 implementation-effectiveness design was selected to enable simultaneous evaluation of implementation and effectiveness under real-world conditions. Evaluation is guided by the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework and the Practical, Robust Implementation and Sustainability Model (PRISM). RE-AIM provides the overarching framework for evaluation of effectiveness and implementation outcomes, while PRISM is used to identify barriers, enablers, contextual factors, adaptations, and determinants of implementation and sustainability. In addition to implementation and effectiveness evaluations, the study will examine health economic considerations associated with implementation of AOBP in general practice and will explore longer-term health outcomes through approved linkage to routinely collected administrative and health datasets where available. These evaluations are intended to complement trial findings and inform future implementation, scale-up, and sustainability of AOBP in Australian primary care settings.

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: Patients will be eligible to participate if they meet Australian guideline-recommended criteria for BP measurement, either for absolute CVD risk assessment or for BP assessment as an individual risk factor, and are attending a participating general practice clinic during the study period. Eligible participants include: Adults attending participating general practice clinics who are eligible for BP measurement for absolute CVD risk assessment, including: * Adults aged 45 to 79 years without known CVD * Adults aged 35 to 79 years with diabetes and without known CVD * First Nations peoples aged 30 to 79 years without known CVD Adults eligible for BP assessment as an individual risk factor, including: * First Nations peoples aged 18 to 29 years * Adults aged 18 years and over where BP measurement is clinically indicated based on individual risk factors or clinical judgement (e.g. suspected hypertension from BP measurements outside the clinic, obesity, abnormal cholesterol levels, secondary causes of hypertension, or time elapsed since last BP measurement) Exclusion Criteria: * Patients who are unable to provide informed consent. * Patients whose participation is deemed clinically inappropriate by the treating general practitioner.

Outcomes

Primary Outcomes

The proportion of patients with treated and controlled hypertension, with the primary estimand being the absolute difference in this proportion between the pre-implementation period and 12-month AOBP implementation period.

Hypertension control will be defined according to Australian guideline recommendations using AOBP thresholds (average systolic BP \<135 mmHg and diastolic BP \<85 mmHg). "Treated" refers to patients receiving antihypertensive therapy.