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Assessing cardiovascular risk and treatment benefits
Intervention benefits
Based on the conservative estimate, each intervention such as aspirin, blood pressure treatment
(lowering systolic blood pressure by 10 mm Hg) or lipid modification (lowering LDL-C by 20%)
reduces cardiovascular risk by about 25% over 5 years.
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Risk level:
5-year CV risk (fatal and non-fatal)
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Benefits: NNT for 5 years to prevent on event
(CVD events prevented per 100 people treated for 5 years)
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1 Intervention
(25% risk reduction)
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2 Interventions
(45% risk reduction)
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3 Interventions
(55% risk reduction)
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30%
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13
(7.5 per 100)
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7
(14 per 100)
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6
(16 per 100)
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20%
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20
(5 per 100)
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11
(9 per 100)
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9
(11 per 100)
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15%
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27
(4 per 100)
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15
(7 per 100)
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12
(8 per 100)
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10%
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40
(2.5 per 100)
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22
(4.5 per 100)
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18
(5.5 per 100)
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5%
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80
(1.25 per 100)
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44
(2.25 per 100)
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36
(3 per 100)
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The Framingham coronary prediction algorithm
The Framingham coronary prediction algorithm (see Appendix VIII) is used to assess cardiovascular risk and it provides patient’s absolute risk of total CHD risk (risk of developing one of the following; angina pectoris, myocardial infarction, or coronary disease death) over the course of 5-10 years.
How to use the tables
- Identify the table relating to the person’s sex, diabetic status, smoking history and age.
- Within the table choose the cell nearest to the person’s age, blood pressure and TC: HDL ratio.
- For example, the lower left cell contains all non-smokers without diabetes who are less than 45 years and have a TC: HDL ratio less than 4.5 and a blood pressure less than 130/80 mm Hg.
Please note:
- When the systolic and diastolic values fall in different risk levels, the higher category applies.
- People who fall exactly on a threshold between cells are placed in the cell indicating higher risk.
Notes for users of this risk algorithm
After determining the cardiovascular risk using the Framingham table, the following groups should be moved up by one risk category (5%). This is because their cardiovascular risk may be underestimated in the Framingham risk equation.
- People with a family history of premature coronary heart disease or ischemic stroke in first-degree male relative before the age of 55 years or a first-degree female relative before the age of 65 years.
- People from Indian subcontinent.
- People with both diabetes and microalbuminuria.
- People who have had type 2 diabetes for more than 10 years or who have an HBA1c consistently greater than 8%.
- People with metabolic syndromes.
Please note:
- These adjustments should be made once only for people who have more than one criteria
- The maximum adjustment is 5%.
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