Related Experiment Videos
Lipid lowering and coronary heart disease risk: how appropriate are the national guidelines?
1West Gippsland Hospital, Warragul, VIC. bforge@absoluterisk.com
Insights
Current Australian guidelines for prescribing lipid-lowering drugs inadequately identify high-risk individuals for coronary heart disease prevention. The Framingham risk estimates offer a more rational approach to guideline development for primary prevention.
Area of Science:
- Cardiology
- Preventive Medicine
- Health Policy
Background:
- Current Australian guidelines for lipid-lowering drug prescription in primary prevention of coronary heart disease (CHD) are in place.
- Assessing the effectiveness of these guidelines in identifying high-risk individuals is crucial for optimizing primary prevention strategies.
Purpose of the Study:
- To evaluate the accuracy of Australian Pharmaceutical Benefits Scheme (PBS) and National Heart Foundation (NHF) guidelines in identifying patients who would benefit from lipid-lowering drugs for primary CHD prevention.
- To compare guideline-based eligibility with absolute CHD risk calculated using the Framingham formula.
Main Methods:
- A cross-sectional study of 230 patients without a history of vascular disease who were dispensed lipid-lowering drugs in rural Victoria.
- 10-year absolute CHD risk was calculated using the Framingham formula.
- Patients' eligibility for lipid-lowering drugs was assessed against current PBS and NHF guidelines.
Main Results:
- Twenty-six percent of patients on lipid-lowering drugs did not meet PBS guidelines.
- Among patients eligible under PBS guidelines, 39% had a 10-year CHD risk <15%.
- Adherence to guidelines could exclude 14% (PBS) and 7% (NHF) of patients with a 10-year CHD risk >15% from treatment.
Conclusions:
- Australian guidelines for lipid-lowering drug prescription are suboptimal for identifying high-risk individuals for primary CHD prevention.
- The Framingham risk estimates, reflecting a continuous risk-factor relationship, provide a more robust basis for treatment guidelines.
- Revising guidelines based on absolute risk assessment is recommended for more effective primary prevention of coronary heart disease.
Objective:
To assess the effectiveness of current Australian guidelines for prescribing lipid-lowering drugs in identifying high-risk individuals in primary prevention of coronary heart disease.
Design And Setting:
Coronary heart disease risk profiles were obtained for 280 consecutive patients dispensed lipid-lowering drugs in rural Victoria. Their 10-year absolute risk of coronary heart disease was determined using the Framingham formula. PATIENTS were categorised according to their eligibility for lipid-lowering drugs as defined by current Pharmaceutical Benefits Scheme (PBS) and National Heart Foundation (NHF) guidelines.
Patients:
Complete data were available for 230 patients dispensed lipid-lowering drugs. Of these, the 138 patients (60%) with no history of vascular disease are the subjects of our study.
Main Outcome Measures:
Proportion of patients with various 10-year coronary heart disease thresholds (15%, 20% and 30%), compared with their eligibility for lipid-lowering drugs based on Australian PBS and NHF guidelines.
Results:
Twenty-six per cent of patients with no history of vascular disease who are currently dispensed lipid-lowering drugs do not fulfil PBS guidelines for treatment. Of patients conforming with PBS guidelines as suitable for lipid-lowering drugs, 39% (95% CI, 30%-49%) had a 10-year risk of coronary heart disease of less than 15%. A similar proportion (41% [95% CI, 32%-50%]) had a 10-year risk of coronary heart disease of less than 15%, but were eligible for lipid-lowering drugs according to NHF guidelines. Adherence to PBS and NHF guidelines in patients currently dispensed lipid-lowering drugs would result in as many as 14% (95% CI, 8%-21%) and 7% (95% CI, 3%-12%) of patients, respectively, not being eligible for treatment, despite having a 10-year risk of coronary heart disease greater than 15%.
Conclusions:
Australian guidelines for prescribing of lipid-lowering drugs are poor discriminators of absolute risk of coronary heart disease in primary prevention. Strategies based on the continuous relationship between risk-factor intensity and absolute coronary heart disease risk, such as the Framingham risk estimates, provide a more rational basis for formulating treatment guidelines.