Introduction
Cardiovascular disease burden
Cardiovascular disease (CVD) is the leading global cause of disability-adjusted life-years and mortality, accounting for approximately one-third of deaths globally.1 In Australia, CVD carries a significant burden of disease.2 3 Internationally, CVD-related morbidity and mortality rates have improved significantly in recent decades. Between 2010 and 2019, there was an 11.1% decrease in age-standardised rates of death due to CVD (14.7% for cerebrovascular disease and 9.7% for ischaemic heart disease).4 5 Despite these improvements, the global decline in CVD incidence and mortality has faltered, and even reversed in younger people.6 7 A further aspect of the Australian context is that Aboriginal and/or Torres Strait Islander peoples experience CVD at higher rates than non-Indigenous Australians but are undertreated for risk factors and receive poorer ongoing management,8 9 outcomes reflected in First Nations populations in Canada10 and the USA.11
Absolute cardiovascular risk assessment
Modifiable risk factors for CVD are well established (including high blood pressure, high blood cholesterol, smoking and diabetes). Better management of these risk factors has been a major reason for declines in rates of CVD in advanced countries in recent years. Nine potentially modifiable risk factors have been deemed to account for 90% of the Population Attributable Risk of myocardial infarction in men and 94% in women in a major international study.12
The additive effects of individual risk factors in CVD and a need to target preventive treatment to those patients at greatest risk of CVD has led to the concept of a management tool based on absolute cardiovascular risk (ACVR) rather than independent management of individual risk factors.13 Calculation of ACVR involves the use of multivariable risk assessment tools (CVD risk scores or calculators) to estimate an individual’s CVD risk. These scores or calculators incorporate relevant CVD risk factors and arrive at a summary estimate of the individual’s personal absolute risk of experiencing a major cardiovascular event (typically, in the following 5 or 10 years).14 The intensity of management (including antihypertensive and lipid-lowering treatment) should then be considered accordingly.15 As long ago as 1993, recommendations have been made for antihypertensive and lipid-lowering treatment decisions to be based on ACVR calculation rather than relative risk.16 17
ACVR algorithms include those for estimating risk of fatal or non-fatal coronary heart disease developed from Framingham, USA data,18 for estimating risk of any CVD mortality from European data,19 and for estimating risk of incident CVD (coronary heart disease, stroke and transient ischaemic attack) from the UK data.20 In Australia, use of the Australian cardiovascular risk calculator, based on the Framingham Risk Equation and recalibrated for the Australian population, is recommended by the National Heart Foundation.14
Implementation of ACVRa in general practice
General practice is the primary mechanism for CVD risk identification and management in Australia.21 All GPs and GP registrars (vocational specialist trainees in family medicine/general practice) will have access to ACVR risk calculators in their practice software, plus easily accessible online availability. Hardcopy ACVR risk calculation algorithms (using colour-coded charts) are also widely available.22 Australian GP practice software programs (and online ACVR calculators) produce a percentage estimate of ACVR (eg, % risk of incident CVD in the next 5 years) based on Framingham data. Printed materials (and some online sites) produce an ACVR risk stratification classification, for example, ‘low risk’ (less than 10% risk of CVD within the next 5 years), ‘moderate risk’ (10%–15%) and high risk’ (greater than 15%).14
Routine use of ACVRa has been shown to promote better health outcomes through improved cardiovascular management.23–25 However, implementation in Australian general practice has proved problematic: a 2020 survey found that 78% of Australian GPs use ACVRa, with just 45% reporting high assessment rates.26 In baseline audits of general practice in a recent Australian RCT, only 48% of patients aged 45–69 had ACVRa recorded in their notes.27 Thus, there appears to be only modest uptake of ACVRa in Australian general practice. Available literature demonstrates similarly poor utilisation of CVD risk assessment tools among primary care practitioners internationally, with reported rates of frequent/regular use as low as 17% in the USA28 and 32.4% in Ireland.29 In Belgium, 53% of GPs reported never using a global (absolute) CVD risk assessment tool.30 While a 2020 survey in the UK revealed high self-reported utilisation of CVD risk assessment among GPs across a number of CVR risk tools, how frequently these tools are used remains unclear.31
GPs continue to focus on individual risk factors (blood pressure and cholesterol) rather than absolute CVD risk.32 33 This represents a significant evidence-practice gap in CVD management.34 35 It has been estimated that only 7% of Australians aged 45–74 years attending general practice have had an ACVR score calculated.36 Qualitative Australian research suggests that implementing ACVR-based management in general practice is complex and may require multifaceted approaches.37 38 There remains significant scope for increasing the proportion of eligible patients receiving ACVRa.
With the disease burden of CVD projected to increase significantly in this decade,39 ‘increased efforts are needed to tackle these major risk factors’.40 GP registrars (specialist vocational trainees in general practice/family practice) are a group of particular interest given that registrars (during their 18 months of general practice-based training) comprise approximately 13% of current GP workforce by head count41 and are at a career stage when they are establishing clinical approaches and practices that may be long-lasting. Exploring the use of ACVRa by GP registrars will be valuable in determining uptake and understanding associations of ACVRa. An understanding of these and other contextual aspects of ACVR use will inform the multifaceted approaches required to increase the use of ACVRa in primary care, including during the vocational training of GPs.
In this study, we aimed to establish the prevalence and associations of GP registrars performing in-consultation ACVRa.