Practice nurses and the prevention of cardiovascular" disease and stroke: a literature review

to promote evidence-based practice. Part I1: hypertension, raised blood cholesterol lack of exercise and obesity P. Crookes, S. Davies, A. McDonnell, J. Shewan

Patrick Crookes PhD, BSc, RGN, Cert Ed, Senior Lecturer, University of Wollongong, Australia Sue Davies MSc, BSc, RGN, RHV, Lecturer in Nursing, School of Nursing and Midwifery, University of Sheffield, UK A n n McDonnell MSc, BSc, RGN, RNT, Lecturer in Nursing, School of Nursing and Midwifery, University of Sheffield, UK Jane Shewan BEd, RGN, Staff Nurse, Barnsley District General Hospital, UK Correspondence to: Sue

Davies, Samuel Fox House, Northern General Hospital, Herries Road, Sheffield $5 7AU, UK.TeI: 0114 226 6865 E-mail: [email protected],uk

This is the second of two papers reviewing the evidence for interventions aimed at reducing the incidence of risk factors for cardiovascular disease (CVD) and stroke in p r i m a r y care settings. The first paper considered the role of practice nurses in the p r i m a r y prevention of CVD and stroke and interventions relating to smoking cessation. This paper reviews the evidence for interventions in relation to hypertension, raised blood cholesterol, lack of exercise and obesity. The paper concludes with a s u m m a r y of practice indicators for reducing risk factors for CVD and stroke, based upon the current state of knowledge, which are particularly relevant to practice nurses and others engaged in health promotion. As new evidence becomes available, it is essential for practitioners to update and maintain t h e i r knowledge base in this area if the m a x i m u m reduction in the incidence of CVD and stroke is to be achieved.

Keywords: practice

nurses, cardiovascular disease, stroke, risk factors, prevention

INTRODUCTION This is the second of two papers which aim to review the evidence in relation to interventions aimed at the reduction of risk factors for cardiovascular disease (CVD) and stroke in primary care settings. The review was carried out in the context of research to examine the extent to which the interventions made by practice nurses in relation to the primary prevention of CVD and stroke are supported by research (McDonnell et al 1997).

Clinical Effectiveness in Nursing (1997) I, 198-2059 1997Harcourt Brace& Co. Ltd

However, the findings of the review have implications for all health care professionals who are engaged in health promotion aimed at reducing t h e incidence of CVD and stroke. The first paper describes the methods of the review and provides an overview of research into the general effectiveness of practice nurses in the field of CVD and stroke prevention. Specific interventions aimed at helping clients to stop smoking are then examined. This paper reviews the evidence for interventions in relation to the following risk

Prevention of cardiovasculardiseaseand stroke

factors: hypertension, raised blood cholesterol, lack of exercise and obesity. While some research evaluating approaches to the provision of lifestyle advice is also considered, the paper does not claim to review all the evidence in relation to strategies for helping patients to change health-related behaviour. A comprehensive discussion of these strategies is provided by Mason et al (1994). Rather, the focus of this paper is on identifying the rationale for specific interventions in relation to the main risk factors for CVD and stroke.

HYPERTENSION MacMahon et al (1990) estimate that an individual with a diastolic blood pressure greater than 110 mm Hg, has 12 times the risk of stroke and six times the risk of cardiovascular disease (CVD) than someone with a diastolic BP of 80 mm Hg or less. Collins et al (1990) suggest that a 5-6 mm Hg drop in diastolic blood pressure is associated with a 20-25% drop in CVD mortality. A meta-analysis of eight published RCTs concluded that anti-hypertensive therapy in the elderly prevents major coronary events and prolongs life, with significant treatment effects observed within 5 years (Pearce et al 1995). The National Forum for Coronary Heart Disease Prevention (1988) assert that a blood pressure at or below 120/80 mm Hg is associated with low risk of CVD and stroke. Reducing blood pressure to within these parameters would constitute a major contribution to public health, particularly with regard to CVD and stroke. The role of nurses in general practice in relation to hypertension involves the referral of patients identified as hypertensive to GPs lk)r further assessment and treatment, supporting and educating patients about non-pharmacological measures for reducing their blood pressure and evaluating the effectiveness of measures taken. Drug treatment currently falls within the domain of medical practice.

Pharmacological measures While one set of guidelines on the management of hypertension is based on the assessment of absolute risk of CVD and stroke (Jackson et al 1993), the majority are based on blood pressure thresholds. A working party for the British Hypertension Society (BHS) recommended the commencement of pharmacological treatment in patients under 80 years with a diastolic blood pressure greater than 100 mm Hg, or between 90 and 99 mm Hg with target organ damage (e.g. eyes, left ventricle, kidneys) (Sever et al 1993). Recommendations based upon the results of six trials (SHEP Co-operative Research Group 1991; MRC Working Party 1992) also suggest that patients aged 60-80 years should be treated if they have a systolic blood pressure

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greater than 160 mm Hg. For people over 80 years, Sever et al (1993) recommend treatment when systolic blood pressure is greater than 160 mm Hg and/or diastolic blood pressure is above 90 mm Hg. These patients should be referred to their GP, whether or not they are currently receiving antihypertensive therapy.

Non-pharmacological measures The importance of non-pharmacological measures for all hypertensives has been clearly identified (Sever et al 1993; Alderman 1994). These include weight reduction for those who are obese, dietary salt reduction, regular exercise, limiting alcohol intake and stopping smoking (Sever et al 1993). For mild hypertensives, such lifestyle modifications have been found to reduce blood pressure by 10.5/8.2 mm Hg, compared with 18.2/12.8 mm Hg reductions with drugs (Treatment of Mild Hypertension Research Group 1991). For more severe hypertensives, such measures can reduce the need for high dose and/or multiple drug regimens. Modification of dietary sodium and potassium alone have been identified as capable of lowering blood pressure. Law et al (1991) suggest that a reduction of sodium or increase in potassium of 20 mmol per day, is associated with approximately 2 mm Hg reduction. If applied to the population, a 5-10% reduction in cardiovascular disease and a I0% decrease in the prevalence of hypertension could be expected. Such modifications are possible by simple measures such as eating 1-2 helpings of citrus fruit per day and not adding salt to fbod at the table. A recent systematic review also demonstrated that dietary supplementation with fish oils (omega-3 polyunsaturated fatty acids) reduced both systolic and diastolic blood pressure in untreated hypertensive patients (Appel et al 1993).

Summary of interventions for reducing hypertension Nurses in general practice should refer hypertensive patients (see above criteria) to the GR whether the patient is currently undergoing anti-hypertensive therapy or not. Non-pharmacological measures to reduce blood pressure should be encouraged in all hypertensive patients. This should include a recommendation to limit dietary salt intake. Nurses should be involved in patient follow-up to evaluate the effectiveness of anti-hypertensive therapy.

RAISED B L O O D C H O L E S T E R O L Raised blood cholesterol and C V D risk A systematic review demonstrates that when blood cholesterol rises from 5-7.8 mmol/litre, the ageadjusted 6-year death rate rises three-fold

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(Freemantle et al 1993). However, in isolation from other risk factors, for example smoking and hypertension, blood cholesterol level is a poor predictor of cardiovascular disease. Very high levels, i.e. greater than 7.8 mmol/litre (Trent Health 1993) are typically due to genetic predisposition (e.g. familial hyperlipidaemia) and are predictive of CVD (Freemantle et al 1993). Reductions in plasma cholesterol can be achieved through drug treatment or dietary modification. The Royal College of General Practitioners (1992) recommend that some form of treatment is indicated at levels above 5.2 mm/l. This may comprise advice on lifestyle, a lipid lowering diet, further investigation or drug treatment depending on the plasma level.

Reduction in blood cholesterol and C V D risk Mann's meta-analysis of six large-scale dietary trials (1987) found a 15% drop in CVD mortality rates for a 10% reduction in blood cholesterol. A metaanalysis of trials using diet o r drugs to reduce blood cholesterol levels by Peto et al (1985), showed an associated reduction of CVD mortality rates with decreases in blood cholesterol. Following an analysis of 41 studies, Law et al (1994) conclude that a long-term reduction in serum cholesterol of 0.6 mrnll lowers the risk of ischeamic heart disease by 50% at age 40, falling to 20% at age 70.

Practice nurses and reduction in blood cholesterol Dietary modification Whereas drug treatment involves the administration of lipid lowering agents which are at present prescribed only by doctors, dietary recommendations are within the scope of nursing practice. The HEA (1993) identifies the 'step 1 diet', or 'general lipid-lowering regime'. This requires: 9 9 9 9

less than 30% energy from total fat; a polyunsaturated to saturated fat ratio of 1:0; a dietary cholesterol intake of less than 300 mg daily; a reduced energy intake to achieve desirable weight, if necessary.

Lewis et al (1989) claim that such a diet can reduce blood cholesterol by between 10-25%. However, Freemantle et al's systematic review (Freemantle et al 1993) demonstrates that while having no adverse effects, this diet is unlikely to have any great impact on individual mortality risk. The more restrictive 'step 2 diet' (with very low levels of saturated fat and cholesterol) has been shown to reduce blood cholesterol by only 5% in those people with moderately raised cholesterol (Freemantle et al 1993).

A number of studies have demonstrated that community nurses are moderately effective, in terms of reducing plasma cholesterol levels, through the use of lifestyle assessment and modification programmes (Gibbins et al 1993; British Family Heart Study Group 1994; Imperial Cancer Research Fund OXCHECK Study Group 1 9 9 5 ; Lindholm et al 1995). As already discussed, little detail is given regarding the exact nature of the interventions employed in these studies (Mullen et al 1992). However, there appears to be a heavy emphasis on dietary modification, using techniques such as demonstrating the 'hidden' fat content of food and assessing the nutritional value of an individual's 'weekly shopping basket' along with the 'patient' (Lindholm et al 1995). There is some published work on the relative effectiveness of different ways of giving dietary advice. For example, there is evidence to suggest that advice from a dietitian supplemented with a diet sheet is more effective in reducing blood cholesterol than printed materials alone (Heller et al 1989; Cousins et al 1992). More intensive approaches, usually involving several episodes of input (e.g. lectures, interviews, discussions) and follow-up have also been found to be successful in reducing blood cholesterol levels in a range of agegroups (Gemson et al 1990; McGowan et al 1994).

Screening Guidelines based on the recommendations of the Coronary Prevention Group, the British Heart Foundation and the Royal College of General Practitioners advise that screening for raised plasma cholesterol should be prioritized according to a number of factors, including existing CVD and family history of hyperlipidaemia (Royal College of General Practitioners 1992). The Effective Health Care Group systematic review (Freemantle et al 1993) demonstrates that population screening is contra-indicated for the following reasons: 9 9

9

9

blood cholesterol by itself is a poor predictor of individual risk of CVD; cholesterol measurement is subject to sources of error which can result in misclassification particularly when desk-top analysers are used; cholesterol-lowering treatments are effective at reducing mortality only in the small number of patients at high overall risk - those identified purely on the basis of cholesterol levels are unlikely to benefit; the labeling of asymptomatic people may result in a reduced quality of life and the adoption of a 'sick role'.

Since the publication of this systematic review the results of a number of large-scale RCTs evaluating the effectiveness of the newer cholesterol-lowering agents (the 'statins') have been published (Byrne and Wild 1996; Ramsay et al 1996). These

Prevention of cardiovascular disease and stroke studies indicate that statins offer benefits for primary and secondary prevention of CVD. Current recommendations for secondary prevention give priority to patients with established CVD (or clinically overt atherosclerotic disease) and a serum cholesterol of 5.5 mm/1 or higher. However, for primary prevention, treatment should be targeted at a CVD risk threshold and not a cholesterol threshold (Ramsay et al 1996).

Summary of interventions for reducing blood cholesterol Particular emphasis should be placed upon identifying and treating people with hyperlipidaemia (> 7.8 mmol/litre). Treatment with drugs and/or diet should be considered in those with a blood cholesterol level greater than 5.2 mmol/litre. Dietary recommendations should be based around the 'step 2 diet'. Practical techniques for demonstrating the 'hidden' fat content of food and assessing the nutritional value of an individual's weekly shopping basket appear to be at least moderately effective in encouraging dietary modification, as does supplementing advice with written materials such as diet sheets, supported by regular follow-up. Population screening of blood cholesterol should be discouraged. Blood cholesterol measurement should only be undertaken using regularly calibrated machinery, preferably within an accredited laboratory.

PHYSICAL I N A C T I V I T Y A N D EXERCISE Nicholl et al (1994) calculate that in England and Wales, up to 32% of CVD and hypertension and 26% of strokes could be avoided if the population took an adequate amount of exercise. Such claims are supported by research trials into the effects of exercise on the incidence of CVD (Morris 1980; Paffenbarger 1986; Paffenbarger 1993; Morris et al 1990) and hypertension (Blair et al 1984; Powell et al 1987; American College of Sports Medicine 1993; Fagard 1993). In a study of more than 17 000 civil servants for example, Morris et al (1990) found that regular vigorous exercise reduced the risk of expected cardiac events by up to 50%. Vigorous exercise has also been reported as increasing diet-induced reductions in cholesterol levels (Fricker 1996). Furthermore, supervised physical activity programmes after myocardial infarction have been associated with a reduction in mortality of up to 20% (Oldridge et al 1988; O'Connor et al 1989). The question remaining is what constitutes an adequate amount of exercise? Until recently, the accepted view was that three 20-minute periods of vigorous aerobic exercise each week reduced the incidence of CVD (Morris et al 1987) and that this level should be recommended by health professionals. This is still the recommendation for those who wish to maximize their aerobic

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fitness a s w e l l a s reducing mortality (Whitehead 1995). However, recent recommendations from expert panels on both sides of the Atlantic - the UK Health Education Authority (Killoran et al 1995) and the Centre for Disease Control and Prevention and the American College of Sports Medicine (Pate et al 1995) - suggest that 30 minutes of moderate exercise on at least 5 days per week can achieve health benefits sufficient to minimize mortality. This is the central theme of the recently-launched HEA campaign 'Fit For Life' (March 1996). A major factor in this change in policy has been the recognition that 'vigorous' exercise is often beyond the ability (real or perceived) of most people, particularly elderly people. Lack of time and a sense of not being a 'sporty type' may also act as barriers to taking exercise (Health Education Authority and the Sports Council 1992). The benefits of moderate exercise such as brisk walking, social dancing or any other activity which causes the person to feel warm and slightly out of breath (American Colleges of Sports Medicine 1990) provide potential for health gain as well as being accessible to a larger proportion of the population, including the elderly, people with disabilities and those with pre-existing CVD and hypertension. Although there is now general agreement about the most appropriate level of exercise to promote cardiovascular health, there is limited evidence in relation to the most successful strategies for helping individuals to maintain such a level. A review of the effectiveness of physical intervention studies undertaken by Hillsdon (1995) revealed only ten studies worldwide on this topic and none in the UK. Effective interventions tended to incorporate factors such as flexibility to undertake exercise informally (in other words not in formal settings such as sports or fitness centres), frequent professional follow-up by telephone or in person to offer encouragement; a recommendation of moderate exercise and the promotion of walking as the form of exercise.

Summary of interventions for physical inactivity in order to achieve health benefits to minimize mortality, including mortality related to cardiovascular disease and stroke, health professionals should recommend 30 minutes of moderate exercise on at least 5 days per week. While there is limited empirical evidence on the best way to promote this level of activity, it seems probable that personal encouragement for patients, either by telephone or face-toface, could be an important factor.

I N A P P R O P R I A T E DIET This review has already examined the impact of diet on cholesterol levels and hypertension, the relationship between dietary sodium/potassium and

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hypertension and methods which may be effective in maximizing the effectiveness of dietary advice. What remains to be discussed is the relationship between diet, obesity and cardiovascular disease and stroke. There will also be a brief consideration of health professionals' readiness and ability to provide dietary advice. The Allied Dunbar National Fitness Survey (Health Education Authority and the Sports Council 1992) estimated that 40% of the UK population are overweight, and attributed this to unsatisfactory diet and inactivity. Recommendations regarding levels of exercise and possible mechanisms for encouraging such activity were made earlier in this review. A direct relationship between increasing bodyweight and a rise in both blood cholesterol and blood pressure has been identified (Hubert et al 1983; Kaplan 1989). The authors of this review could find no clear indication of risk of CVD and stroke associated with obesity alone. However, in an overview of cardiovascular risk factors, Cunningham (1992) cites two studies which focus on this area and highlights that researchers were only able to establish an independent relationship between baseline bodyweight and CVD after 26 years of follow-up (Hubert et al 1983; Rabkinn et al 1977). Studies such as the Nurses Health Study (Manson et al 1990) which involved an 8-year follow-up of over 115 000 women, indicate that the relative risks of nonfatal myocardial infarction and fatal CVD increased significantly from 1.0 to 3.3 in association with the Quetelet Index of subjects (weight in kilos divided by height in metres squared) after adjustment for age and smoking. There have also been a number of studies which demonstrate that weight loss is accompanied by a reduction in cardiovascular risk factors including blood pressure, left ventricular hypertrophy, raised blood glucose and cholesterol levels (MacMahon et al 1985; MacMahon et al 1986; Hubert et al 1987). The most appropriate dietary advice based on current knowledge is that individuals should attempt to maintain their weight within an acceptable body mass index range (BMI) for their height. It may seem simplistic to state that the patient's BMI should be calculated first; however, Francis et al (1989) found that 35 of 104 GPs and community-based nurses gave advice designed to promote weight loss to patients who were not in fact overweight. COMA recommendations (Committee of Medical Aspects on Food 1-984) suggest that weight reduction and control should be approached by reducing total dietary fat intake (particularly saturated fat), increasing consumption of fibre-rich starch foods, increasing consumption of fruit and vegetables and decreasing the amount of added sugar in the diet (including 'hidden' sugar in processed foods). Parallels can be drawn between these recommendations and the 'general lipid-lowering regime' referred to earlier (Health Education Authority 1993) to help reduce blood cholesterol levels.

Comments made earlier in relation to cholesterol levels for achieving changes in diet and lifestyle can also be applied to weight reduction, namely the translation of broad recommendations into clearly defined actions and the use of a multi-faceted approach including follow-up. As with smoking cessation, an assessment of the client's 'readiness to change' and understanding of the risks associated with being overweight should be made prior to offering dietary advice. There is some research-based evidence to suggest that primary health care workers may lack the requisite skills and knowledge to offer dietary advice. Francis et al (1989) identified that GPs and community nurses sometimes lack the necessary knowledge about nutrition to give appropriate advice to patients, or are unable to translate such knowledge into practical advice, tailored to the needs of an individual patient (Murray et al 1993). Research into the ability and motivation of staff to undertake dietary counselling is therefore essential in order to establish training needs.

Summary of interventions in relation to inappropriate diet Individuals should be advised to achieve and maintain a bodyweight which places them within the 'normal' range of the body mass index. They can best achieve this by following a diet similar to the 'general lipid-lowering regime', supplemented with an adequate intake of fresh fruit and vegetables. Providing practical examples of ways in which diet can be modified, and regular follow-up after an initial assessment of readiness to change may also be beneficial in helping an individual to lose weight.

GENERAL S U G G E S T I O N S IN RELATION T O T H E PROVISION OF LIFESTYLE ADVICE A recurrent theme from the preceding discussions on lifestyle modification is the apparent benefit of multi-faceted approaches to intervention, along with systematic review and follow-up of clients. There is also some evidence that the effectiveness of one-toone health promotion strategies could be maximized by concentrating on patients who are motivated to change. Prochaska and DiClemente have developed a comprehensive model to show the process through which people change addictive behaviours (Prochaska & DiClemente 1986). The model suggests that individuals move through a series of stages when attempting to modify their own behaviour patterns. The process begins with pre-contemplation (when the individual is not at all interested in changing their behaviour), through contemplation to preparing to change, making changes and finally maintaining change. There is evidence to suggest that individuals who leap into action without

Prevention of cardiovasculardiseaseand stroke 203

adequate preparation or contemplation are a high risk for relapse (Prochaska et al 1992). Although the model was originally developed from research on smoking, it has been found to be a useful framework for considering other types of behaviour such as eating and taking exercise, on the grounds that these can also develop into habits which are difficult to break (Orford 1985). The main implication for health professionals is the need to tailor interventions to the readiness to change of the individual (Rollnick et al 1993). For example, those who are unsure about stopping smoking need the opportunity to weigh up the advantages and disadvantages of changing their behaviour rather than direct advice (Stott et al 1994). The importance of adopting an appropriate negotiating style has also been highlighted (Rollnick et al 1992). CONCLUSION While there is abundant evidence on the benefits of reducing risk factors for cardiovascular disease and stroke for individuals, the evidence for interventions to achieve such a reduction is less well established. This two-part review has attempted to identify the rationale for focusing effort on risk factor reduction as well as considering the evidence for interventions which nurses in a range of care settings can adopt with clients and patients aimed specifically at reducing risk factors for CVD and stroke. These are summarised in Appendix I, and it is suggested that these interventions should form the basis for the development of guidelines and protocols in relation to health p r o m o t i o n activities a i m e d at p r i m a r y p r e v e n t i o n in this field. In the a b s e n c e o f p r e d i c t i v e e v i d e n c e , nurses m u s t m a k e use o f the best available e v i d e n c e to g u i d e their practice, but readers are r e m i n d e d that the ' b e s t e v i d e n c e ' is likely to c h a n g e o v e r t i m e as the results o f n e w research become

available.

W h i l e this t w o - p a r t

r e v i e w m a y be a useful tool to g u i d e c u r r e n t p r a c tice, h e a l t h care practitioners m u s t m a i n t a i n a n d update their k n o w l e d g e in this field as n e w e v i d e n c e emerges. REFERENCES

American College of Sports Medicine 1993 American College of Sports Medicine position stand: physical activity, physical fitness and hypertension. Medicine and Science in Sports and Exercise 10:2-10 American Colleges of Sports Medicine 1990 The recommended quantity and quality of exercise for developing and maintaining cardiomspiratory and muscular fitness in healthy adults. Medicine and Science in Sports and Exercise 22:265-274 Appel LJ, Mi]ler ER, Seidler A J, Whelton PK 1993 Does supplementation of diet with 'fish oil' reduce blood pressure? Archives of Internal Medicine 153:1429-1438 Blair SN, Goodyear NN, Gibbons LW, Cooper KH 1984 Physical fitness and incidence of hypertension in healthy normotensive men and women. Journal of the American Medical Association 252:487-490

British Family Heart Study Group 1994 British family heart study: its design and method, and prevalence of cardiovascular risk factors. British Journal of General Practice 44:62-67 Byrne CD, Wild SH 1996 Lipids and secondary prevention of ischaemic heart disease. British Medical Journal 3 t 3: 1273-1274 Collins R, Peto R, MacMahon S e t al 1990 Blood pressure, stroke and coronary heart disease: part 2: short-term reductions in blood pressure: overview of randomised trials in their epidemiological context. Lancet 335: 827-838 Cousins JH, Rubovits DS, Dunn JK, Reeves RS, Ramirez AG, Foreyt JP 1992 Family versus individually orientated intervention for weight loss in MexicanAmerican Women. Public Health Reports 107: 616-621 Cunningham S 1992 The epidemiologic basis of coronary disease prevention. Nursing Clinics of North America 27(1): 153-170 Fagard F 1993 Physical fitness and blood pressure. Journal of Hypertension 11 (Suppl 5): 47-52 Francis J, Roche M, Mant D, Jones L, Fullard E 1989 Would primary health care workers give appropriate dietary advice after cholesterol screening? British Medical Journal 298:1620 1622 Fremnantle N, Long A, Mason J, Sheldon T, Song F, Wilson C 1993 Cholesterol screening and treatment. Effective Health Care (6) Fricker J 1996 Exercise increases diet-induced drops in cholesterol. The Lancet 347:819 Gemson DH, Sloan RP, Messeri P, Goldberg IJ 1990 A public health model for cardiovascular risk reduction: impact of cholesterol screening with brief non-physician counselling. Archives of Internal Medicine 150: 985489 Gibbins RL, Gibbins MR, Gibbins PB 1993 Effectiveness of programme for reducing cardiovascular risk for men in one general practice. British Medical Journal 306:1652-1656 Health Education Authority 1993 Nutrition interventions in primary care. A literature review Health Education Authority, London Heahh Education Authority and the Sports Council 1992 Allied Dunbar National Fitness Survey: Main Findings. Sports Council & Health Education Authority, London Heller RF, Elliot H, Bray AE, Alabaster M 1989 Reducing blood cholesterol levels in patients with peripheral vascular disease: dietitian or diet fact sheet? Medical Journal of Australia 151:566-568 Hillsdon M 1995 Randomised controlled trials of physical activity promotion in free-living populations: a review. Journal of Epidemiology and Community Health 49: 448-453 Hubert HB, Eaker ED, Garrison R J, Castelli WP et al 1987 Life-style correlates of risk factor change in young adults: an 8-year study of coronary heart disease factors in the Framingham Heart Study. American Journal of Epidemiology 125:812 Hubert HB, Feinleib M, McNamara PM, Castelli WP 1983 Obesity as an independent risk factor lbr cardiovascular disease: a 26-year follow-up of participants in the Framingham Heart Study. Circulation 67:968 Imperial Cancer Research Fund OXCHECK Study Group 1995 Effectiveness of health checks conducted by nurses in primary care: final results of the OXCHECK Study. British Medical Journal 310(29 April): 1099-1103 Jackson R, Barham R Bills J et al 1993 Management of raised blood pressure in New Zealand: a discussion document. British Medical Journal 307:107-110 Kaplan NM 1989 The deadly quartet: upper body obesity, glucose intolerance, hyper-tryglycerideridaemia, and hypertension. Archives of Internal Medicine 149:1514

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Killoran A J, Fentem P, Caspersen C 1995 Moving On: A Summary. Health Education Authority, London Law M, Frost C, Wald N 1991 By how much does dietary salt reduction lower blood pressure? British Medical Journal 302:819-824 Law MR, Wald NJ, Thompson SG 1994 By how much and how quickly does reduction in serum cholesterol concentration lower risk of ischaemic heart disease? British Medical Journal 308:367-373 Lewis B, Assman G, Mancini M, Stein Y 1989 Handbook of coronary heart disease prevention Publisher/place/pages? Lindhnlm LH, Ekbom T, Dash C, Eriksson M, Tibblin G, Schersten B 1995 The impact of health care advice given in primary care on cardiovascular risk. British Medical Journal 310:1105-1112 MacMahon S, Peto R, Cutler J, Andrews G, Blacker RB 1990 Blood pressure, stroke, and coronary heart disease: I. Prolonged differences in blood pressure: Prospective observational studies corrected for dilution bias. Lancet 335:765 MacMahon SW, MacDonald GJ, Bernstein Let al 1985 Comparison of weight reduction with metoprolol in treatment of hypertension in young overweight patients. Lancet 1:1233 MacMahon SW, Wilcken DEL, MacDonald GJ,1986 The effect of weight reduction on left ventricular mass. New England Journal of Medicine 314:334 Mann JI 1987 Clinical trials of cholesterol lowering. Lipid Review MSD l: 26-34 Mason P, Hunt P, Raw M, Sills M 1994 Helping People Change. Health Education Authority, London Manson JE, Colditz GA, Stampfer MJ 1990 A prospective study of obesity and risk of coronary heart disease in women. New England Journal of Medicine 322:882 McDonnell A, Davies S, Browne J, Shewan J, Crookes P 1997 A detailed investigation of factors associated with the implementation of research-based knowledge by practice nurses in the prevention of cardiovascular disease and stroke. University of Sheffield, Sheffield McGowan MP, Joffe A, Duggan AK, McCay PS 1994 Intervention in hypercholesterolaemic college students: a pilot study. Journal of Adolescent Health 15: 155-162 Morris JN 1980 Vigorous exercise in leisure time: protection against coronary heart disease. The Lancet ii: 765-774 Morris JN, Clayton D, Everitt MG, Semmence AM, Burgess E 1990 Exercise in leisure time: coronary attack and death rates. British Heart Journal 63:325-334 Morris JN Everitt MG, Semmence AM 1987 Coronary Heart Disease and Exercise. Health Trends 19: 13-16. MRC Working Party 1992 Medical Research Council trial of treatment of hypertension in older adults: principal results. British Medical Journal 304:405-411 Mullen PD, Mains DA, Velez R 1992 A Meta-analysis of controlled trials of cardiac patient education. Patient Education and Counselling 19:143-162 Murray S, Narayan V, Mitchell M, Witte H 1993 Study of dietetic knowledge among members of the primary health care team. British Journal of General Practice 43: 229-231 National Forum for Coronary Heart Disease Prevention 1988 Coronary heart disease prevention: action in the UK 1984-1987. Health Education Authority, London Nicholl J, et al 1994 Health and healthcare costs and benefits of exercise. Pharmaco Economics 5:109-122 O'Connor G, Buring J, Yusuf S e t al 1989 An overview of randomised trials of rehabilitation with exercise after myocardial infarction. Circulation 80:234-244 Oldridge N, Guyatt G, Fischer M, Rimm A 1988 Effects on quality of life with comprehensive rehabilitation after

acute myocardial infarction. Journal of the American Medical Association 67:1084-1089 Orford J 1985 Excessive appetites: a psychological review of addiction. Wiley, Chichester Paffenbarger RS, Jr, Hyde RT, Wing AL, Asieh CC 1986 Physical activity all-cause mortality, and longevity of college alumni. New England Journal of Medicine 314: 605-613 Paffenbarger RS et al 1993 The association of changes in physical activity level and other lifestyle characteristics with mortality among men. New England Journal of Medicine 328(8): 538-545 Pate RR, Pratt M, Blair S, et al 1995 Physical Activity and Public Health: a recommendation from the Centres for Disease Control and Prevention and the American Colleges of Sports Medicine. Journal of the American Medical Association 273(5): 402-407 Pearce KA, Fnrberg CD, Rushing J 1995 Does antihypertensive treatment of the elderly prevent cardiovascular events or prolong life? A meta-analysis of hypertension treatment trials. Archives of Family Medicine 4(11): 943-950 Peto R, Ynsuf S, Collins R 1985 Cholesterol lowering trial results in the epidemiological context. Circulation 72 (Suppl iii): 451 Powell K, Thompson R Casperson C, Kendrick J 1987 Physical activity and the incidence of coronary heart disease. Annual Review of Public Health 8:253-287 Prochaska J, DiClemente C 1986 Towards a comprehensive model of change. Plenum, New York Prochaska J, DiClemente C, Velicer W, Rossi J 1992 Criticisms and concerns of the transtheoretical model in the light of recent research. British Journal of Addiction 87:825-835 Rabkin SW, Mathewson FA, Hsu PH 1977 Relation of bodyweight to development of ischaemic heart disease in a cohort of young North American men after a 26 year observation period: The Maitoba Study. American Journal of Cardiology 39:452 Ramsey LE, Haq IU, Jackson PR, Yen WW, Pickin DM, Payne JN 1996 Targeting lipid-lowering drug therapy for primary prevention of coronary disease: an updated Sheffield table. The Lancet 348:387-388 Rollnick S, Heather N, Bell A 1992 Negotiating behaviour change in medical settings: the development of brief motivational interviewing. Journal of Mental Health 1: 25-37 Rollnick S, Kinnersley R Stott N 1993. Methods of helping patients with behaviour change. British Medical Journal 307:188-190 Royal College of General Practitioners 1992 Guidelines for the management of hyperlipidaemia in general practice. Royal College of General Practitioners, London Sever E Beevers G, Bulpitt C et al 1993 Management Guidelines in Essential Hypertension: report of the second working party of the British Hypertension Society. British Medical Journal 306:983-987 S HEP Co-operative Research Group 1991 Prevention of stroke by antihypertensive drug treatment in older persons with isolated systolic hypertension. Journal of the American Medical Association 265:3255-3264 Stott N, Kinnersley P, Rollnick S 1994 The limits to health promotion. British Medical Journal 309:971-972 Treatment of Mild Hypertension Research Group 1991 The treatment of mild hypertension study: a randomised placebo-controlled trial of nutritional-hygiene regimen alone with various drug monotherapies. Archives of Internal Medicine 151:1413 1423 Trent RHA 1993 The Health Gain Investment Programme: Coronary Heart Disease and Stroke. Trent Regional Health Authority, Sheffield Whitehead M 1995 Health Update 5: Physical activity. Health Education Authority, London

Prevention of cardiovasculardiseaseand stroke

Research-Based Indicators for Nursing Practice in Relation to CVD and Stroke Prevention Smoking Clear, repeated advice to stop smoking supported by a range of techniques: 9 9 9 9 9

provision of leaflets negotiating dates for stopping giving patients feedback on exhaled carbon monoxide levels patient follow-up nicotine replacement therapy (particularly in those motivated to stop)

Hypertension Referral of hypertensive patients to GP according to the following criteria: 9

9 9

under 80 years with diastolic greater than 100 mm Hg (or between 90 and 99 mm Hg with target organ damage) aged 60-80 years with systolic greater than 160 mmHg above 80 years with systolic greater than 160 mmHg and/or diastolic greater than 90 mmHg

Non-pharmacological measures should be encouraged in all hypertensive patients, including limiting dietary salt.

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Raised blood cholesterol Screening patients with existing CVD and family history of hyperlipidaemia. Population screening is contra-indicated. Measurement should only be undertaken using regularly calibrated machinery, preferably within an accredited laboratory. Treatment with drugs or diet considered in those with a blood cholesterol level of more than 5.2 mm/1. Encouraging dietary modification (step 2 diet) with use of techniques, such as: 9 9 9 9

demonstrating hidden fat content assessing nutritional value of weekly shop written materials, e.g. diet sheets regular follow-up

Physical Inactivity Recommending 30 minutes of moderate exercise, e.g. brisk walking, on at least 5 days per week. Diet and Obesity Advise to achieve and maintain weight within 'normal' range of BMI. Recommendation of a 'general lipid-lowering regime' supplemented with an increase in fresh fruit and vegetables.