General practitioners’ use of absolute risk versus individual risk factors in cardiovascular disease prevention: an experimental study

Abstract

ObjectiveTo understand general practitioners’ (GPs) use of individual risk factors (blood pressure and cholesterol levels) versus absolute risk in cardiovascular disease (CVD) risk management decision-making.DesignRandomised experiment. Absolute risk, systolic blood pressure (SBP), cholesterol ratio (total cholesterol/high-density lipoprotein (TC/HDL)) and age were systematically varied in hypothetical cases. High absolute risk was defined as 5-year risk of a cardiovascular event >15%, high blood pressure levels varied between SBP 147 and 179 mm Hg and high cholesterol (TC/HDL ratio) between 6.5 and 7.2 mmol/L.Setting4 GP conferences in Australia.Participants144 Australian GPs.OutcomesGPs indicated whether they would prescribe cholesterol and/or blood pressure lowering medication. Analyses involved logistic regression.ResultsFor patients with high blood pressure: 93% (95% CI 86% to 96%) of high absolute risk patients and 83% (95% CI 76% to 88%) of lower absolute risk patients were prescribed blood pressure medication. Conversely, 30% (95% CI 25% to 36%) of lower blood pressure patients were prescribed blood pressure medication if absolute risk was high and 4% (95% CI 3% to 5%) if lower. 69% of high cholesterol/high absolute risk patients were prescribed cholesterol medication (95% CI 61% to 77%) versus 34% of high cholesterol/lower absolute risk patients (95% CI 28% to 41%). 36% of patients with lower cholesterol (95% CI 30% to 43%) were prescribed cholesterol medication if absolute risk was high versus 10% if lower (95% CI 8% to 13%).ConclusionsGPs’ decision-making was more consistent with the management of individual risk factors than an absolute risk approach, especially when prescribing blood pressure medication. The results suggest medical treatment of lower risk patients (5-year risk of CVD event <15%) with mildly elevated blood pressure or cholesterol levels is likely to occur even when an absolute risk assessment is specifically provided. The results indicate a need for improving uptake of absolute risk guidelines and GP understanding of the rationale for using absolute risk.

Predictors of cholesterol treatment discussions and statin prescribing for primary cardiovascular disease prevention in community health centers

“…(16) For example, participants with a diagnosis of hyperlipidemia, but without diabetes or CHD, were more likely to be prescribed a statin than those with diabetes or CHD, but without hyperlipidemia, in spite of the established higher risk status of those in the latter group (probability 0.59, 95% CI 0.54-0.64 versus 0.04, 95% CI 0.02-0.06).…”

Cohort study investigating the relationship between cholesterol, cardiovascular risk score and the prescribing of statins in UK primary care: study protocol

“…After adjusting for other CVD risk factors, lipid profile has been found to predict statin initiation in a US study 32 and a randomised theoretical experiment in Australia highlighted clinicians' preferences for managing individual risk factors over absolute risk. 33 To further compound the problem, patients find it difficult to make decisions based on future risks and tend to preferentially focus on cholesterol levels when considering taking statins. 34 35 In 2014, guidelines for England and Wales on lipid modification reduced the predicted risk threshold at which patients should be offered statins from a 20% 10-year risk to 10%.…”

New Strategy to Reduce the Global Burden of Stroke

“…The time and costs associated with these arrangements may be a deterrent for many individuals, particularly those who are socioeconomically disadvantaged or live in remote rural communities. Third, even in high-income countries, the use of high-risk CVD prevention strategies by medical professionals is poor 27 as is the adherence of patients to the recommended medications and lifestyle for primary and secondary CVD prevention. 33 Fourth, the tools that are commonly used to predict the risk of stroke/CVD 34,35 are not easily accessible in multiple languages, not aimed at younger age groups (<55 years), do not account for racial/ethnic and geographical differences, or are designed for use by health professionals only.…”

“…[27][28][29] This high absolute risk of CVD is usually defined as a risk of ≥15% during the next 5 years. 27 This approach is valid and suitable for selecting people at high risk of acute CVD and for monitoring their progress in CVD prevention in the outpatient setting. However, in terms of effective primary stroke/ CVD prevention, there are several issues with this approach.…”