Health promotion priorities for general practice: constructing and using “indicative prevalences”BMJ 1994; 308 doi: https://doi.org/10.1136/bmj.308.6935.1019 (Published 16 April 1994) Cite this as: BMJ 1994;308:1019
- B G Charlton,
- N Calvert,
- M White,
- G P Rye,
- W Conrad,
- T van Zwanenberg
- Department of Epidemiology and Public Health, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH
- Northern Regional Health Authority, Newcastle upon Tyne NE6 4PY
- Conrad and Rye, Jesmond, Newcastle upon Tyne NE2 1PQ
- Correspondence to: Dr van Zwanenberg.
Objective : To construct indicative prevalences for a range of diseases and risk markers and use them in planning health promotion interventions in primary health care.
Design: Indicative prevalences comprised point prevalence, incidence, and mortality measures. Use of data from Office of Population Censuses and Surveys, Northern Regional Health Authority, and Newcastle health and lifestyle survey 1991, and research papers to determine prevalence adjusted for age and sex in a hypothetical practice with a list of 10 000 patients.
Setting : Newcastle upon Tyne, England.
Results : Indicative prevalences were highest for common risk markers such as failure to achieve exercise targets (6871), moderate to extreme obesity (2785), and smoking (2689); moderate for overt disease such as angina (175) and stroke (20/year); and low for events such as suicide (1/year) and deaths from malignant melanoma (2/10 years).
Conclusions : Given limited time and resources, brief interventions to reduce smoking and the systematic case finding and management of patients with hypertension, angina, and previous myocardial infarction are likely to be the highest priorities for health promotion in primary care.
Public health implications
Public health implications
The role of primary health care teams in health promotion is increasing
In this study national and local data were used to determine indicative prevalences of mortality, morbidity, and risk markers for a hypothetical general practice population
Indicative prevalences can be adapted to any general practice to help determine priorities for health promotion
Brief interventions to reduce smoking and the optimal management of hypertension, angina, and previous myocardial infarction should be priorities
In recent years health promotion has become an increasingly important part of primary health care.1,2 This trend is part of a movement towards the integration of public health responsibilities into general practice.*RF 3-7* Primary health care teams have had to assume broad new strategic responsibilities for maintaining and promoting the health of patients on the practice list as well as continuing to provide 24 hour clinical services. With limited time and resources it is essential to set priorities.
The 1990 general practitioner contract incorporated several public health elements: population monitoring through child health surveillance, three yearly health checks for adults and screening for people over 75; assessment of health needs through recording referrals to consultants; and health promotion clinics.1 The changes were criticised,*RF 8-12* and payments for health promotion clinics turned out to be much higher than expected. Furthermore, the quality and uptake of clinics was was uneven and not related to the needs of the population.13 The public health role has been further expanded by the new arrangements for health promotion and chronic disease management in primary health care introduced in July 1993.2
To show how practice data might be used to set priorities we generated “indicative prevalences” for a hypothetical average general practice with a list size of 10 000 in Newcastle upon Tyne (the district health authority and family health services authority are coterminous with the city boundary). Indicative prevalences are measures of point prevalence, incidence, and mortality rates generated for disease and risk markers. Conditions were drawn from the national priorities defined by the 1993 modifications to the general practitioner contract and key areas in the Health of the Nation.14 Newcastle upon Tyne is of particular interest because the district is the major urban centre of population in the Northern health region. The region has the highest prevalence of coronary heart disease and stroke and also the worst all cause standardised mortality ratio in England.15 Furthermore, the recently published Newcastle health and lifestyle survey has generated a unique database for this community.16,17
We derived data for indicative prevalences from three main sources: the Newcastle health and lifestyle survey 199116,17; mortality data from the Office of Population Censuses and Surveys death tapes for 1988- 92; and admissions for asthma, accidental injury, and coronary artery bypass surgery from Northern Regional Health Authority 1990-2. These data were supplemented with data from other published sources if local figures were not available (box). We used 1991 census data18 to calculate incidence of prevalence when these were not already determined.
Data sources for calculating indicative prevalences
* Newcastle health and lifestyle survey 199116,17 - sex specific prevalences in 10 year age bands for people aged 16-74
* Office of Population Censuses and Surveys - death tapes for Newcastle upon Tyne District Health Authority 1988-92 used to calculate average annual age and sex specific mortality
* Northern Regional Health Authority - Mean annual number of admissions calculated and used to derive age and sex specific admission rates with population of Newcastle in 1991 census18 as denominator
* Annual report of Newcastle genitourinary medicine clinic19 - Number of new cases of gonorrhoea in 1992 used to calculate crude incidence with 1991 census population as denominator
* Cannon et al20 - Crude prevalence of angina applied directly to hypothetical practice
* Health and lifestyle survey21 - sex specific prevalences of hypertension for 10 year age bands in adults over 18 applied to hypothetical population
* NHS Management Executive22 - crude incidence of ischaemic attacks and prevalence of stroke
* Dennis et al23 - crude rates of transient ischaemic attack
* Bamford et al24 - crude incidence of stroke
We created a hypothetical average general practice population to reflect the demographic structure of the population of Newcastle upon Tyne. The proportion of men and women in each 10 year age group of the Newcastle population, derived from the 1991 census, was multiplied by 10 000 to give the number in each age and sex band of the hypothetical practice population. Direct standardisation was used in most cases to adjust data from the original sources to provide indicative prevalences for the hypothetical practice.25 We applied age specific rates for men and women to 10 year age and sex groups of the hypothetical practice to give the expected numbers of people with the condition or risk factor in the practice population. The numbers in each age and sex group have been summed and overall practice figures are presented for each indicator.
Indicative prevalences are approximate and we have therefore rounded them to the nearest whole number and presented them without confidence intervals to avoid any spurious sense of accuracy. Where age specific rates were not available we estimated the number of expected cases without standardisation. For data from the Newcastle health and lifestyle survey indicative prevalences were calculated only for the ages 16 to 74 years.
Table I lists the indicative prevalences for conditions covered by the new arrangements for health promotion and chronic disease management in general practice. Table II lists prevalences for the other key areas in cancer, sexual health, accidents, and mental illness. We have used incidence of gonorrhoea as a proxy measure for new cases of AIDS and suicide rate as an index of psychiatric illness as suggested in the Health of the Nation.14
Indicative prevalences varied widely. The highest prevalences were for risk markers such as failure to achieve the exercise target (6871), moderate to extreme obesity (2785), and smoking (2689). Common diseases had intermediate prevalences (angina 175; diabetes 165). Some of the diseases identified as key areas in Health of the Nation had low indicative prevalences, especially for mortality (cervical cancer four deaths/10 years; malignant melanoma two deaths/10 years; one suicide/year).
The figure represents the “iceberg” of coronary heart disease and stroke in primary care. The iceberg metaphor emphasises the relation between the relatively small burden of overt disease (above the water line) and the great mass of hidden risk markers that can lead to disease (below the water line). The figure shows how a group of related procedures, diseases, and risk markers can be summarised to give an impression of the scale of each problem and the possibilities for intervention by a primary health care team.
We used data on a district of about 300 000 people to derive indicative prevalences for an average practice list of 10 000 patients. The indicative prevalences can be used, after adjustment for list size, to give an idea of prevalences for any practice. It should be remembered, however, that the data we used are of variable quality and completeness and most of the data refer to the Newcastle population, which has higher mortality and morbidity than many other districts.15
Primary health care teams can use indicative prevalences to modify national priorities in the light of the needs of their patients or to confirm that their current priorities are reasonable. As computerised information systems become more reliable and complete, specific information on prevalence, incidence, and mortality could be generated by each practice. Prevalences for ischaemic heart disease and its risk factors were generated for a Newcastle practice with a list size of 4100 which had a highly developed information system. The results were consistent with the indicative prevalences presented here (D L Whitford, personal communication).
Planning health promotion
Health promotion activities should be planned on the basis of the prevalence of a particular risk marker or condition, its seriousness, and the cost effectiveness of intervention. Recent evidence has suggested that blanket health promotion may not be cost effective.29 Indicative prevalences can also be used to select an intervention that can produce observable benefit relatively quickly. One of the problems of health promotion is that people promoting health seldom see a return for their efforts, and this undermines motivation. One area where benefit would occur quickly is smoking. General practitioners can give brief advice and information opportunistically, which is cheap and effective, and the effect on risk of myocardial infarction and lung cancer is seen over just a few years.30 There is preliminary evidence that similar brief interventions may be effective in reducing the harm associated with hazardous alcohol consumption.31 Moderate to severe obesity and lack of exercise are more common than smoking, but they do not seem to be such serious risk factors for disease and the effectiveness of intervention is largely unproved.32
Hypertension is another serious common condition in which patients could benefit from intervention. Only about half of the patients with hypertension are currently detected in normal practice,33 and a more systematic approach is required.34 A recent meta-analysis has shown that aspirin can reduce mortality and morbidity in a wide range of cardiovascular diseases.35 Primary health care teams could usefully concentrate on identifying and monitoring patients who would benefit from aspirin. For instance, our data suggest that practices might expect to find about 175 patients with angina in a population of 10 000; these could be identified by contacting patients who are prescribed nitrates.20,36 A similar process of case finding, preventive treatment, and audit could be devised to prevent recurrence of myocardial infarction by prescribing prophylactic aspirin and β blockers.37
Indicative prevalences fit well with innovative models of primary health care. For instance, a model of preventive medicine through anticipatory care in general practice has been developed over several decades, based on opportunistic screening and interventions informed by epidemiological studies.3,4 Focused and personal intervention can be more effective and cheaper than population based interventions or multiphasic screening and advice.4,38,39 However, it is probably not possible to cover all patients comprehensively and reliably without a team based practice organisation, efficient patient information systems, and an inbuilt audit cycle.40
General practice has many advantages for pursuing health promotion since about 85% of patients will consult a member of the primary health care team each year.16,17 In the past general practitioners have mainly reacted to patients' problems rather than acting to prevent problems. The role of the general practitioner as personal physician and the gatekeeper to secondary care is vital and must be sustained. But anticipatory care is possible and effective if practices have high motivation, sufficient resources, trained staff, appropriate organisation, and a targeted approach based on research.40 The expansion of the primary health care team to include practice nurses, health visitors, and other clinical professionals has brought anticipatory care closer.
Indicative prevalences may be useful in suggesting how to set priorities which make the most effective use of limited resources and are appropriate to the practice. The objective is to concentrate effort so as to produce an observable improvement in the health of patients over a reasonably short time. Our data suggest that brief interventions directed at reducing smoking and optimal management of patients with hypertension, angina, and myocardial infarction are good candidates.
We thank Penny Williams and Lynn Richardson for secretarial help; Mick Sharp for drawing the figure; John Stevenson for help in accessing and interpreting the Northern Regional Health Authority database; and other members of the Newcastle health and lifestyle survey 1991 research team for preparing the dataset. The Newcastle health and lifestyle survey is funded by Newcastle Health Authority and Newcastle Family Health Services Authority and is supported by the Department of Epidemiology and Public Health at the University ofNewcastle upon Tyne.