The CPG was established in 1979. It is the only UK charity dedicated solely to the prevention of coronary heart disease, and aims to contribute to a 30% reduction in deaths from the disease by the year 2000. To achieve this CPG works in a variety of ways with health workers, government, the EC, the media and others to develop healthier public policy. The Group does not accept funding from food, tobacco or drug companies.

Primary health care teams have a great deal to offer in healping people to reduce the high rates of coronary heart disease (CHD) in the United kingdom.  People can be helped to reduce their risk by giving up smoking, adpting a healthier diet, taking regular exercise, and by the treatment of high blood pressure 1.

This Action Plan aims to help proctices target their action against CHD more effectively and efficiently.  It provides practices with a flexible system of deciding which patients should receive a particular level of care which takes into account the resources they have available and wish to devote to CHD prevention.  It proposes that practices should allocate patients into two groups: a Special Care Group who will receive apecial attention because of their relativley high level of risk and a General Advice Group who will receive less attention because of their lower level of risk.

The Action Plan assumes a selective approach to cheolesterol testing recommended in a policy statement of the Cpg, endorsed by the British Heart Foundation and 24 other organisations 1,2,3. However it can be used by practices who are undertaking any level of testing.

Published September 1991

Members of the Working Group

Professor Geoffrey Rose (Chair)
Department of Epidemiology and Population Sciences, London
School of Hygiene and Tropical Medicine

Dr Godfrey Fowler
Clinical Reader in General Practice, Department of Public Health and Primary Care, University of Oxford

Professor Andrew Haines
Department of Primary Health Care, University College & Middlesex School of Medicine

Dr Bobbie Jacobson
Director of Public Health, City and Hackney Health Authority

Professor Desmond Juries
Medical Director, British Heart Foundation

Michael O’Connor
Director, LSHTM (1991)

Dr Mike Rayner
Senior Research Officer, LSHTM (Secretary)

Dr Theo Schofield
Lecturer in General Practice, Department of Public Health and Primary Care, University of Oxford

Professor Jim Shepherd
Professor of Pathological Biochemistry, Royal Infirmary, Glasgow

Nicki Spiegal
Primary Care Facilitator, Aldermoor Health Centre, Southampton

Professor Hugh Tunstall-Pedoe
Director, Cardiovascular Epidemiology Unit, Ninewells Hospital, Dundee

Joan Welsh Health Promotion Facilitator, Newcastle.

THE SPECIAL CARE GROUP

Special preventive action against CHD for a patient will involve a 4,5,6 range of strategies. It will certainly involve lifestyle advice that should entail discovering knowledge, attitudes, beliefs and behaviour. It will mean following up patients to assess the effectiveness of the advice provided. It may lead to drug treatment for a minority.

The number of patients for whom a practice can provide such special preventive care, i.e. the size of their Special Care Group, will depend upon available resources. Comprehensive risk assessment and individualised advice requires considerable resources and most practices will only be able to provide special preventive care to patients at a relatively high level of coronary risk. A recent study suggests that almost three-quarters of patients aged 5-64 need advice or treatment as a result of one or more risk factors for CHD and more than a third require attention for two or more risk factors 7. This Action Plan provides a rational way of addressing this problem.

As a minimum the Special Care Group should consist of those who are at high risk of CHD because of an established clinical condition. However it is highly desirable that other patients at high overall risk because of elevated risk factor levels should also be provided with special preventive care. These two categories of patients are defined below.

CLINICAL RISK PATIENTS – people who have recognised CHD, have diabetes or are receiving drug treatment for hypertension or hyperlipidaemia.

These patients should be provided with special care because they are at high risk of CHD and there is extensive evidence for the benefits of risk reduction 2. Even where these patients are receiving care they may not have had an overall assessment of coronary risk and would benefit from this 8.

We estimate that such “Clinical Risk Patients” will constitute about one in eight of an average practice population (14% of 40-59 year olds according to the Scottish Heart Health Study 9, 15% of 35-64 year olds according to the OXC HECK Study 7) but practices may be able to make a more accurate calculation from their records.

MULTIPLE RISK PATIENTS – other people who are at high risk of CHD.

We recommend that other people should be targeted for special care according to their modifiable risk of CHD based on those major risk factors that can be readily assessed. We suggest the Dundee Coronary Risk-Disk should be used for this purpose 10, but the Action Plan could be adapted for use with other scoring systems, for example the British Regional Heart Study (RHS) scoring system 11.

A simple way of targeting “Multiple Risk Patients” for special care is to allocate people to this group if they have two or more major risk factors for CHD. Such a system fails to take into account that the interaction between risk factors is multiplicative rather than additive, nor does it allow for the graded nature of many risk factors 12,13.

The Dundee Coronary Risk-Disk calculates risk from the individual’s level of the three major modifiable risk factors for CHD: smoking, blood pressure and blood cholesterol and it reflects their multiplicative action 10. The Risk-Disk works on the slide rule principle to give two measures of modifiable coronary risk:

  1. The Dundee Risk Score, which is a measure of the patient’s risk of a myocardial infarction or coronary death over five years relative to their sex and age group. A low score is good: a high score is bad. A score of x implies twice the risk of score of x/2.
  2. The Dundee Risk Rank which indicates the patient’s risk in relation to their position in a queue of 100 people of the same sex and age. A high rank (low number) is bad: a low rank (high number) is good.

A Dundee Coronary Risk Rank or Score can be calculated by using an estimate for the cholesterol level based on the average value for that person’s age and sex, but substitution of a real blood cholesterol reading for the estimate will improve the accuracy.

The Risk-Disk is designed in such a way that the proportion of Multiple Risk Patients (expressed as the percentage of a particular age/sex group) for whom a practice decides it can provide special preventive care is equal to the lowest Dundee Rank for those patients. If for example a practice decides that they can provide special preventive care for 10% of people aged 40-59, in addition to their Clinical Risk Patients, then 40-59 year olds should be allocated to the Special Care Group if they have a Dundee Rank of 10 or above.

The Action Plan makes use of this property of the Dundee Risk-Disk. If any other scoring system were to be used, then the distribution of scores in the Multiple Risk Patients would need to be estimated. The distribution of RHS scores in all men aged 40-59 has been published 11,14 but is not yet available for Multiple Risk Patients of this age/sex group.

THE GENERAL ADVICE GROUP

All those outside the Special Care Group should receive some advice about diet, exercise and smoking because everyone in the UK is at high risk of CHD, by international standards. General advice will probably include the provision of leaflets and possibly referral to other sources of information and care. Attention to the Special Care Group should not diminish existing effort to advise all smokers, borderline hypertensives, those who are overweight, etc.

Preventing CHD in Primary Care: ACTION PLAN

CARRYING OUT THE ACTION PLAN

DECISIONS

Firstly the following three decisions need to be made:

  1. The number of people to be included in the Special Care Group. (Special Care Group = Clinical Risk Patients + Multiple Risk Patients). We estimate that Clinical Risk Patients will constitute about one in eight of an average practice population. The additional number of Multiple Risk Patients will depend on available resources.
  2. Whether Multiple Risk Patients should include women as well as men. Although coronary risk is lower in women, CHD is the major cause of death in both sexes 15.
  3. The age group for Multiple Risk Patients. We suggest men and women aged 40-59, because the available evidence on the benefits of risk reduction suggests that middle age should be a priority 2,12,13.

Having chosen the number and age/sex profile of Multiple Risk Patients a practice can now define their threshold Dundee Rank. Expressed as a percentage of a given age and sex group, the number of Multiple Risk Patients equals the threshold Dundee Rank for those patients.

RISK ASSESSMENT

Once you have made the above decisions and calculated the threshold Dundee Rank for Multiple Risk Patients, the Action Plan can now be put into operation using the accompanying flow chart (above).

For all patients we recommend recording the following:

  1. Whether they have a history of CHD or diabetes, or are on drug treatment for hypertension or hyperlipidaemia.
  2. Whether a parent or sibling has had a heart attack and at what age, or whether one of these has ever been diagnosed as suffering from familial hyperlipidaemia.
  3. Details of their smoking history, i.e. if a nonsmoker, whether they have ever smoked and if so when they gave up. If a smoker, whether they smoke a pipe, cigars or cigarettes, and how many cigarettes each day.
  4. Their systolic and diastolic blood pressure.

For the following patients we recommend cholesterol testing:

  1. Clinical Risk Patients (i.e. people with diagnosed CHD or diabetes, or who are on drug treatment for hypertension.
  2. People with a close family history of premature CHD i.e. siblings or parents with major manifestations before the age of 50 for men, or 55 for women. People with parents or siblings with familial hyperlipidaemia. People with xanthomas at any age. or xanthelasmas or corneal arcus under the age of 50. We estimate that this group will represent 5-10% of an average practice population  over and above the Clinical Risk Patients 9,16.
  3. People of the chosen age and sex for your Multiple Risk Patients whose Risk Rank, on the basis of smoking behaviour, blood pressure and estimated blood cholesterol is above, or close to, the selected threshold value for Multiple Risk Patients. We suggest that people with an estimated Dundee Rank of, for example, 5 – 10 ranks below the selected value should be given a blood cholesterol test to ensure that the Special Care Group includes everybody in the chosen age/sex group with a real Dundee Rank above the threshold, i.e. if the selected maximum value for the Special Care Group is 10, people should be given a cholesterol test if their estimated Dundee Rank is higher than 15 or 20.

For the patients indicated in paragraphs b. and c. above it will be necessary to recalculate their Dundee Rank using their real, as opposed to estimated, blood cholesterol level, before allocating a proportion to the Special Care Group.

ALLOCATION TO GROUPS

Patients can now be allocated to one of the following groups:

1. The Special Care Group = the Clinical Risk Patients + the Multiple Risk Patients

2. The General Advice Group.

In practice the numbers in each group will tend to vary between practices and so the selected threshold rank for Multiple Risk Patients may need to be adjusted in the light of experience.

A PRACTICAL EXAMPLE

The Action Plan can be used in different types of practice, in different circumstances and with different levels of cholesterol testing. It can, for example, help in the planning and establishment of health promotion clinics or with efforts to improve an existing opportunistic prevention programme. Here is an imaginary example of how the Action Plan can be used:

Practice A is a group practice with a list of 10,000 (7,000 patients aged 18-74). It has five partners with two practice nurses. The practice decides that the practice nurses should hold ten health promotion clinics a week (450 a year). Each clinic will be for ten patients.

Under the new GP Contract the practice needs to offer health checks to all their patients aged 18-74 every three years and to new registrations. They estimate, therefore, that they will need to perform 3,000 health checks each year and decide that these should be performed within the health promotion clinics.

This means that, in addition to initial health checks, 750 patients can be followed up at the health promotion clinics assuming, on average, two follow up appointments (4500 = 3000 /2 = 750). The practice has 1000 patients who are already under treatment for CHD, hypertension, hyperlipidaemia or diabetes (Clinical Risk Patients); they decide that 500 of these could be followed up in the health promotion clinics, leaving 250 places for Multiple Risk Patients (750 500 = 250).

The practice decides to target men and women aged 40-59 and find from their records that they have 2000 in this age group. This means that people aged 40-59 who have an Dundee Rank of 12.5 or more can be followed up (250/2000 x 100 = 12.5).

References

1. London School of Hygiene and Tropical Medicine Risk assessment in the prevention of coronary heart disease: a policy statement. Br J Gen Prac 1990; 40:467-469.

2. Standing Medical Advisory Committee. Blood cholesterol testing: the cost-effectiveness of opportunistic testing. Department of Health 1990.

3. King’s Fund Forum. Blood cholesterol measurement in the prevention of coronary heart disease: consensus statement. King’s Fund, London, 1989.

4. Baron JA, Gleason R, Crowe B, Mann JI. Preliminary trial of the effect of general practice based nutritional advice. Br J Gen Prac 1990;40:137-141.

5. Kottke TE, Battissa RN, DeFries CH, Brekke ML. Attributes of successful smoking cessation interventions in medical practice: a meta-analysis of 39 controlled trials. J Amer Med Soc 1988; 259: 2883-9.

6. Wallace P, Cutler S, Haines A. Randomised controlled trial of general practioner intervention in patients with excessive alcohol consumption. Br Med J 1988; 297: 663-8.

7. Imperial Cancer Research Fund OXCHECK Study Group. Prevalence of risk factors for heart disease in OXCHECK trial: implications for screening in primary care. Br Med J 1991; 302:1057-1060.

8. Smith WCS, Lee AJ, Crombie lK, Tunstall-Pedoe H, Control of blood pressure in Scotland: the rule of halves. Br Med J 1990; 300: 981-983.

9. Smith WCS, Tunstall-Pedoe H, Crombie IK, Tavendale R. Concomitants of excess coronary deaths – major risk factor and lifestyle findings from 10,359 men and women in the Scottish Heart Health Study. Scot Med J 1989: 34: 550-5.

10. Tunstall-Pedoe H. The Dundee Coronary Risk-Disk for monitoring change in risk factors. Br Med J 1991 (in press)

11. Shaper AG, Pocock Sj, Phillips AN, Walker M. A scoring system to identify men at high risk of a heart attack- Health Trends 1987; 19: 37-9.

12. Tunstall Pedoe H. Who is for cholesterol testing? Br Med J 1989; 298: 15934.

13. Lewis B, Rose G. Prevention of coronary heart disease: putting theory into practice. J Roy Coll Phys Lond 1991; 25:21-6

14. Wilson A, Morell J. Prevention of heart disease in general practice: the use of a risk score. Health Trends 1991; in press.

15. Office of Population Censuses and Surveys. Deaths by cause: 1988 registrations. London: HMSO, 1989.

16. Mann J I, Lewis B, Shepherd J, Winder AF, Fenster S, Rose L, Morgan B. Blood lipid concentratations and other cardiovascular risk factors: distribution, prevalence, and detection in Britain. Br Med J 1988,.296: 1702-6.