In interpreting the Sheffield tables, it is important to take note of the following points:
– The tables have been developed from epidemiological data (the Framingham study) and show the total cholesterol: HDL cholesterol ratios which confer a risk of coronary events of 3.0% per year. There may be good reason for treating patients at either lower or higher risk.
– The tables can be used to identify patients in whom cholesterol testing is not warranted because treatment would not be indicated at any ratio. For example, there would be little benefit in testing a 50-year-old woman who has no other risk factors.
– A possible weakness of these tables is that they consider hypertension, smoking, diabetes and left ventricular hypertrophy as dichotomous variables (either present or absent). There is thus no ability to discriminate on the basis of the severity of those variables.
– Because these tables are based on risk, rather than the results of controlled clinical trials, they are not the same as the current guidelines for treatment under the Pharmaceutical Benefits Scheme (PBS) in Australia. The PBS guidelines were developed from a consensus conference which not only considered levels of risk, but also considered the results of clinical trials. Compared to treatment based on these tables, treatment according to the PBS guidelines would generally result in treatment of more young people with few risk factors, and treatment of less older people with multiple risk factors.
– The tables use total cholesterol: HDL cholesterol ratios as these are a much better predictor of coronary artery risk than are total cholesterol levels. The PBS guidelines use total cholesterol levels as most long-term clinical trials were based on total cholesterol levels.
– The tables emphasise the size of the differences in absolute risk of coronary events between different patient groups. For example, older men with other risk factors for coronary disease have a high absolute risk of coronary events, even if they have a low total cholesterol: HDL cholesterol ratio. Conversely, young women with few other risk factors have a very low absolute risk of coronary events, even if they have a high total cholesterol: HDL cholesterol ratio.
Instructions
– Choose the table for men or women
– Identify the correct column for smoking, hypertension and diabetes
– In normotensive subjects assume left ventricular hypertrophy absent. In those with hypertension, left ventricular hypertrophy is diagnosed by ECG showing increased voltage and flat or inverted T waves in the left precordial leads. If no ECG is available, assume left ventricular hypertrophy is absent
– Identify the row showing the age of the subject
– Read off the cholesterol: HDL ratio at the intersection of the appropriate column and row:
- If there is no entry, lipids need not be measured
- If there is an entry, measure serum total cholesterol and HDL
- If the average cholesterol: HDL ratio on repeated measurement is at or above the level shown, and the serum total cholesterol is >=5.5 mmol/L, - consider treatment
– If HDL not available, assume 1.2
– The table can be used to look forward to the future need for measurement or treatment at an older age
Notes on use of table
– Do not use for decisions on secondary prevention: patients with myocardial infarct, angina, peripheral vascular disease, or symptomatic carotid disease already have high coronary heart disease risk
– At this risk (3% events per year) treatment with a statin (but not necessarily other drug classes) is justifiable
– Use the table after appropriate advice on smoking, diet and control of systolic blood pressure to <=160 mmHg
– Use the average of two or more measurements of lipids
– Those with total cholesterol: HDL ratio >=8.0 may have familial hypercholesterolaemia
– The table may underestimate coronary heart disease risk in some individuals:
- those with very strong family history of premature coronary heart disease
- those with familial hyperlipidaemia
Permission has been obtained to reprint these tables with slight modifications.
| Sheffield table for primary prevention of coronary heart disease showing serum total: HDL cholesterol ratio conferring an estimated risk of coronary events of 3% per year
|
|
Men: Total cholesterol: HDL cholesterol ratio |
Hypertension
| Yes | Yes | Yes | Yes | Yes | No | Yes | Yes | No | No | Yes | No |
| Smoking | Yes | Yes | No | No | Yes | Yes | Yes | No | Yes | No | No | No |
| Diabetes | Yes | No | Yes | No | Yes | Yes | No | Yes | No | Yes | No | No |
| LVH on ECG* | Yes | Yes | Yes | Yes | No | No | No | No | No | No | No | No |
| Age (years) | | | | | | | | | | | | |
| 70 | 2.0 | 2.0 | 2.0 | 2.5 | 3.0 | 3.6 | 3.8 | 4.4 | 4.6 | 5.3 | 5.6 | 6.7 |
| 68 | 2.0 | 2.0 | 2.1 | 2.6 | 3.2 | 3.8 | 4.1 | 4.7 | 4.8 | 5.6 | 6.0 | 7.1 |
| 66 | 2.0 | 2.0 | 2.2 | 2.8 | 3.4 | 4.0 | 4.3 | 5.0 | 5.2 | 5.9 | 6.3 | 7.6 |
| 64 | 2.0 | 2.0 | 2.3 | 3.0 | 3.6 | 4.3 | 4.6 | 5.3 | 5.5 | 6.3 | 6.8 | 8.1 |
| 62 | 2.0 | 2.2 | 2.5 | 3.2 | 3.8 | 4.6 | 4.9 | 5.6 | 5.9 | 6.7 | 7.2 | 8.6 |
| | | | | | | | | | | | | |
| 60 | 2.0 | 2.3 | 2.7 | 3.4 | 4.1 | 4.9 | 5.2 | 6.0 | 6.3 | 7.2 | 7.7 | 9.2 |
| 58 | 2.0 | 2.5 | 2.9 | 3.7 | 4.4 | 5.3 | 5.6 | 6.5 | 6.7 | 7.7 | 8.3 | 9.9 |
| 56 | 2.1 | 2.7 | 3.1 | 3.9 | 4.7 | 5.7 | 6.0 | 7.0 | 7.2 | 8.3 | 8.9 | 10.6 |
| 54 | 2.3 | 2.9 | 3.3 | 4.2 | 5.1 | 6.1 | 6.5 | 7.5 | 7.8 | 9.0 | 9.6 | |
| 52 | 2.4 | 3.1 | 3.6 | 4.6 | 5.5 | 6.6 | 7.0 | 8.1 | 8.4 | 9.7 | 10.4 | |
| | | | | | | | | | | | | |
| 50 | 2.6 | 3.4 | 3.9 | 5.0 | 6.0 | 7.1 | 7.6 | 8.8 | 9.1 | 10.5 | | |
| 48 | 2.9 | 3.7 | 4.2 | 5.4 | 6.5 | 7.8 | 8.3 | 9.6 | 9.9 | | | |
| 46 | 3.1 | 4.0 | 4.6 | 5.9 | 7.1 | 8.5 | 9.1 | 10.4 | 10.8 | | | |
| 44 | 3.4 | 4.4 | 5.1 | 6.4 | 7.8 | 9.3 | 9.9 | | | | | |
| 42 | 3.8 | 4.8 | 5.6 | 7.1 | 8.6 | 10.2 | 10.9 | | | | | |
| | | | | | | | | | | | | |
| 40 | 4.2 | 5.3 | 6.1 | 7.9 | 9.5 | | | | | | | |
| 38 | 4.7 | 5.9 | 6.8 | 8.7 | 10.5 | | | | | | | |
| 36 | 5.2 | 6.6 | 7.6 | 9.8 | | | | | | | | |
| 34 | 5.8 | 7.5 | 8.6 | | | | | | | | | |
| 32 | 6.6 | 8.5 | 9.7 | | | | | | | | | |
| | | | | | | | | | | | | |
| 30 | 7.6 | 9.7 | | | | | | | | | | |
| 28 | 8.7 | | | | | | | | | | | |
| 26 | 10.2 | | | | | | | | | | | |
| <25 | | | | | | | | | | | | |
| Sheffield table for primary prevention of coronary heart disease showing serum total: HDL cholesterol ratio conferring an estimated risk of coronary events of 3% per year
|
| Women: Total cholesterol: HDL cholesterol ratio |
Hypertension
| Yes | Yes | Yes | Yes | Yes | No | Yes | Yes | No | No | Yes | No |
| Smoking | Yes | No | Yes | Yes | No | Yes | No | Yes | No | Yes | No | No |
| Diabetes | Yes | Yes | No | Yes | No | Yes | Yes | No | Yes | No | No | No |
| LVH on ECG* | Yes | Yes | Yes | No | Yes | No | No | No | No | No | No | No |
| Age (years) | | | | | | | | | | | | |
| 70 | 2.0 | 2.7 | 3.1 | 4.1 | 4.5 | 4.9 | 6.1 | 7.0 | 7.2 | 8.3 | 10.2 | |
| 68 | 2.0 | 2.7 | 3.1 | 4.2 | 4.6 | 5.0 | 6.1 | 7.0 | 7.3 | 8.4 | | |
| 66 | 2.0 | 2.8 | 3.2 | 4.2 | 4.6 | 5.1 | 6.2 | 7.1 | 7.4 | 8.5 | | |
| 64 | 2.0 | 2.8 | 3.2 | 4.3 | 4.7 | 5.2 | 6.4 | 7.3 | 7.6 | 8.7 | | |
| 62 | 2.0 | 2.9 | 3.3 | 4.4 | 4.9 | 5.3 | 6.5 | 7.5 | 7.8 | 9.0 | | |
| | | | | | | | | | | | | |
| 60 | 2.0 | 3.0 | 3.4 | 4.6 | 5.0 | 5.5 | 6.7 | 7.7 | 8.1 | 9.3 | | |
| 58 | 2.1 | 3.1 | 3.6 | 4.8 | 5.2 | 5.7 | 7.0 | 8.0 | 8.4 | 9.6 | | |
| 56 | 2.2 | 3.2 | 3.7 | 5.0 | 5.5 | 6.0 | 7.4 | 8.4 | 8.8 | 10.1 | | |
| 54 | 2.3 | 3.4 | 3.9 | 5.3 | 5.8 | 6.3 | 7.8 | 8.9 | 9.3 | | | |
| 52 | 2.5 | 3.7 | 4.2 | 5.6 | 6.2 | 6.8 | 8.3 | 9.5 | 9.9 | | | |
| | | | | | | | | | | | | |
| 50 | 2.7 | 4.0 | 4.5 | 6.1 | 6.7 | 7.3 | 9.0 | | | | | |
| 48 | 2.9 | 4.3 | 4.9 | 6.6 | 7.3 | 7.9 | 9.8 | | | | | |
| 46 | 3.2 | 4.8 | 5.5 | 7.3 | 8.0 | 8.8 | | | | | | |
| 44 | 3.6 | 5.3 | 6.1 | 8.2 | 9.0 | 9.8 | | | | | | |
| 42 | 4.1 | 6.1 | 7.0 | 9.4 | | | | | | | | |
| | | | | | | | | | | | | |
| 40 | 4.8 | 7.1 | 8.1 | | | | | | | | | |
| 38 | 5.7 | 8.4 | 9.6 | | | | | | | | | |
| 36 | 6.9 | 10.1 | | | | | | | | | | |
| 34 | 8.6 | | | | | | | | | | | |
| <33 | | | | | | | | | | | | |
Risk of coronary event <3.0% per year
* Hypertensive subjects only
