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Explaining the Decline in Coronary Heart Disease Mortality in England and Wales Between 1981 and 2000

Background—Coronary heart disease mortality rates have been decreasing in the United Kingdom since the 1970s. Our study aimed to examine how much of the decrease in England and Wales between 1981 and 2000 could be attributed to medical and surgical treatments and how much to changes in cardiovascular risk factors. Methods and Results—The IMPACT mortality model was used to combine and analyze data on uptake and effectiveness of cardiological treatments and risk factor trends in England and Wales. The main data sources were published trials and meta-analyses, official statistics, clinical audits, and national surveys. Between 1981 and 2000, coronary heart disease mortality rates in England and Wales decreased by 62% in men and 45% in women 25 to 84 years old. This resulted in 68 230 fewer deaths in 2000. Some 42% of this decrease was attributed to treatments in individuals (including 11% to secondary prevention, 13% to heart failure treatments, 8% to initial treatments of acute myocardial infarction, and 3% to hypertension treatments) and 58% to population risk factor reductions (principally smoking, 48%; blood pressure, 9.5%; and cholesterol, 9.5%). Adverse trends were seen for physical activity, obesity and diabetes. Conclusions—More than half the coronary heart disease mortality decrease in Britain between 1981 and 2000 was attributable to reductions in major risk factors, principally smoking. This emphasizes the importance of a comprehensive strategy that promotes primary prevention, particularly for tobacco and diet, and that maximizes population coverage of effective treatments, especially for secondary prevention and heart failure. These findings may be cautiously generalizable to the United States and other developed countries.

Modelling the decline in coronary heart disease deaths in England and Wales, 1981-2000: comparing contributions from primary prevention and secondary prevention

Abstract Objective To investigate whether population based primary prevention (risk factor reduction in apparently healthy people) might be more powerful than current government initiatives favouring risk factor reduction in patients with coronary heart disease (CHD) (secondary prevention). Design, setting, and participants The IMPACT model was used to synthesise data for England and Wales describing CHD patient numbers, uptake of specific treatments, trends in major cardiovascular risk factors, and the mortality benefits of these specific risk factor changes in healthy people and in CHD patients. Results Between 1981 and 2000, CHD mortality rates fell by 54%, resulting in 68 230 fewer deaths in 2000. Overall smoking prevalence declined by 35% between 1981 and 2000, resulting in approximately 29 715 (minimum estimate 20 035, maximum estimate 44 675) fewer deaths attributable to smoking cessation: approximately 5035 in known CHD patients and approximately 24 680 in healthy people. Population total cholesterol concentrations fell by 4.2%, resulting in approximately 5770 fewer deaths attributable to dietary changes (1205 in CHD patients and 4565 in healthy people) plus 2135 fewer deaths attributable to statin treatment (1990 in CHD patients, 145 in people without CHD). Mean population blood pressure fell by 7.7%, resulting in approximately 5870 fewer deaths attributable to secular falls in blood pressure (520 in CHD patients and 5345 in healthy people) plus approximately 1890 fewer deaths attributable to antihypertensive treatments in people without CHD. Approximately 45 370 fewer deaths were thus attributable to reductions in the three major risk factors in the population: some 36 625 (81%) in people without recognised CHD and 8745 (19%) in CHD patients. Conclusions Compared with secondary prevention, primary prevention achieved a fourfold larger reduction in deaths. Future CHD policies should prioritise population-wide tobacco control and healthier diets.

Health effects associated with smokeless tobacco: a systematic review

Background: It is believed that health risks associated with smokeless tobacco (ST) use are lower than those with cigarette smoking. A systematic review was therefore carried out to summarise these risks. Methods: Several electronic databases were searched, supplemented by screening reference lists, smoking related websites, and contacting experts. Analytical observational studies of ST use (cohorts, case-control, cross sectional studies) with a sample size of ⩾500 were included if they reported on one or more of the following outcomes (all cause mortality, oral and pharyngeal cancers, other cancers, cardiovascular diseases, dental diseases, pregnancy outcomes, surgical outcomes). Data extraction covered control of confounding, selection of cases and controls, sample size, clear definitions and measurements of the health outcome, and ST use. Selection, extraction and quality assessments were carried out by one or two independent reviewers. Results: A narrative review was carried out. Many of the studies lacked sufficient power to estimate precise risks, mainly due to the small number of ST users. Studies were often not designed to investigate ST use, and many also had major methodological limitations including poor control for cigarette smoking and imprecise measurements of exposure. Studies in India showed a substantial risk of oral or oropharyngeal cancers associated with chewing betel quid and tobacco. Studies from other regions and of other cancer types were not consistent. Few studies have adequately considered the non-cancer health effects of ST use. Conclusions: Chewing betel quid and tobacco is associated with a substantial risk of oral cancers in India. Most recent studies from the US and Scandinavia are not statistically significant, but moderate positive associations cannot be ruled out due to lack of power. Further rigorous studies with adequate sample sizes are required, especially for cardiovascular disease.

Explaining the recent decrease in coronary heart disease mortality rates in Ireland, 1985–2000

Study objectives: To examine the proportion of the recent decline in coronary heart disease (CHD) deaths in Ireland attributable to (a) “evidence based” medical and surgical treatments, and (b) changes in major cardiovascular risk factors. Design setting: IMPACT, a previously validated model, was used to combine and analyse data on the use and effectiveness of specific cardiology treatments and risk factor trends, stratified by age and sex. The main data sources were published trials and meta-analyses, official statistics, clinical audits, and observational studies. Results: Between 1985 and 2000, CHD mortality rates in Ireland fell by 47% in those aged 25–84. Some 43.6% of the observed decrease in mortality was attributed to treatment effects and 48.1% to favourable population risk factor trends; specifically declining smoking prevalence (25.6%), mean cholesterol concentrations (30.2%), and blood pressure levels (6.0%), but offset by increases in adverse population trends related to obesity, diabetes, and inactivity (−13.8%). Conclusions: The results emphasise the importance of a comprehensive strategy that maximises population coverage of effective treatments, and that actively promotes primary prevention, particularly tobacco control and a cardioprotective diet.

Mortality reductions in patients receiving exercise-based cardiac rehabilitation: how much can be attributed to cardiovascular risk factor improvements?

Background It is unclear how much of the reduction in cardiac mortality in coronary heart disease (CHD) patients with exercise training is the result of direct effects on the heart and coronary vasculature, or to indirect effects, via primary risk factors. Objective The aim of this article was to quantify the cardiac mortality benefits of exercise-based rehabilitation attributable to risk factor reductions versus the direct effects on the heart and vasculature. Methods The IMPACT coronary heart disease model was used to examine the reduction in cardiac mortality attributable to changes in risk factors from a meta-analysis of cardiac rehabilitation randomized, controlled trials. Patients were receiving rehabilitation following an acute myocardial infarction, angina pectoris or revascularization. Outcomes considered were primary risk factors (total cholesterol, systolic blood pressure and smoking behaviour) and cardiac mortality. Results Nineteen exercise-only cardiac rehabilitation trials (including 2984 patients) were identified. Across these trials, exercise training reduced pooled cardiac mortality by 28% (relative risk, 0.72, 95% confidence interval 0.55–0.95), with 30 fewer deaths than in the control group. Applying the CHD model, approximately 17 (58%) of these 30 fewer deaths were attributable to reductions in major cardiovascular risk factors: 7.1 deaths (minimum estimate 6.2, maximum estimate 9.5) attributable to an 18% reduction in smoking prevalence; 5.9 deaths (minimum −0.6, maximum 12.6) to a 0.11 mmol/l reduction in cholesterol, and 4.4 deaths (−1.0 minimum, 6.7 maximum) to a 2.0 mmHg reduction in systolic blood pressure. Conclusions Approximately half of the 28% reduction in cardiac mortality achieved with exercise-based cardiac rehabilitation may be attributed to reductions in major risk factors, particularly smoking. Eur J Cardiovasc Prev Rehabil 13:369–374

Normative data and discriminative properties of short form 36 (SF-36) in Turkish urban population

BackgroundSF-36 has been both translated into different languages and adapted to different cultures to obtain comparable data on health status internationally. However there have been only a limited number of studies focused on the discriminative ability of SF-36 regarding social and disease status in developing countries. The aim of this study was to obtain population norms of the short form 36 (SF-36) health survey and the association of SF-36 domains with demographic and socioeconomic variables in an urban population in Turkey.MethodsA cross-sectional study. Face to face interviews were carried out with a sample of households. The sample was systematically selected from two urban Health Districts in Izmir, Turkey. The study group consisted of 1,279 people selected from a study population of 46,290 people aged 18 and over.ResultsInternal consistencies of the scales were high, with the exception of mental health and vitality. Physical health scales were associated with both age and gender. On the other hand, mental health scales were less strongly associated with age and gender. Women reported poorer health compared to men in general. Social risk factors (employment status, lower education and economic strain) were associated with worse health profiles. The SF-36 was found to be capable of discriminating disease status.ConclusionOur findings, cautiously generalisable to urban population, suggest that the SF-36 can be a valuable tool for studies on health outcomes in Turkish population. SF-36 may also be a promising measure for research on health inequalities in Turkey and other developing countries.

Life-Years Gained From Modern Cardiological Treatments and Population Risk Factor Changes in England and Wales, 1981-2000

OBJECTIVES We estimated life-years gained from cardiological treatments and cardiovascular risk factor changes in England and Wales between 1981 and 2000. METHODS We used the IMPACT model to integrate data on the number of coronary heart disease patients, treatment uptake and effectiveness, risk factor trends, and median survival in coronary heart disease patients. RESULTS Compared with 1981, there were 68230 fewer coronary deaths in 2000. Approximately 925415 life-years were gained among people aged 25-84 years (range: 745 195-1 138 655). Cardiological treatments for patients accounted for approximately 194145 life-years gained (range: 142505-259225), and population risk factor changes accounted for approximately 731270 life-years gained (range; 602695-879430). CONCLUSIONS Modest reductions in major risk factors led to gains in life-years 4 times higher than did cardiological treatments. Effective policies to promote healthy diets and physical activity might achieve even greater gains.

Coronary heart disease policy models: a systematic review

BackgroundThe prevention and treatment of coronary heart disease (CHD) is complex. A variety of models have therefore been developed to try and explain past trends and predict future possibilities. The aim of this systematic review was to evaluate the strengths and limitations of existing CHD policy models.MethodsA search strategy was developed, piloted and run in MEDLINE and EMBASE electronic databases, supplemented by manually searching reference lists of relevant articles and reviews. Two reviewers independently checked the papers for inclusion and appraisal. All CHD modelling studies were included which addressed a defined population and reported on one or more key outcomes (deaths prevented, life years gained, mortality, incidence, prevalence, disability or cost of treatment).ResultsIn total, 75 articles describing 42 models were included; 12 (29%) of the 42 models were micro-simulation, 8 (19%) cell-based, and 8 (19%) life table analyses, while 14 (33%) used other modelling methods. Outcomes most commonly reported were cost-effectiveness (36%), numbers of deaths prevented (33%), life-years gained (23%) or CHD incidence (23%). Among the 42 models, 29 (69%) included one or more risk factors for primary prevention, while 8 (19%) just considered CHD treatments. Only 5 (12%) were comprehensive, considering both risk factors and treatments. The six best-developed models are summarised in this paper, all are considered in detail in the appendices.ConclusionExisting CHD policy models vary widely in their depth, breadth, quality, utility and versatility. Few models have been calibrated against observed data, replicated in different settings or adequately validated. Before being accepted as a policy aid, any CHD model should provide an explicit statement of its aims, assumptions, outputs, strengths and limitations.

Is smokeless tobacco a risk factor for coronary heart disease? A systematic review of epidemiological studies

Background There is on-going debate about the wisdom of substituting smokeless tobacco products for cigarette smoking as a ‘harm reduction’ strategy. It is generally believed that health risks associated with smokeless tobacco use (ST) are lower than those with cigarette smoking. However, the population attributable risk of smoking is higher for cardiovascular diseases than for any cancers, and few studies or reviews have considered the cardiovascular outcomes of ST use. A systematic review was therefore carried out to highlight the gaps in the evidence base. Methods Electronic databases were searched, supplemented by screening reference lists, smoking-related websites, and contacting experts. Analytical observational studies of ST use (cohorts, case-control, cross-sectional studies) were included if they reported on cardiovascular disease (CVD) outcomes, or risk factors. Data extraction covered control of confounding, selection of cases and controls, sample size, clear definitions and measurements of the health outcome and ST use. One or two independent reviewers carried out selection, extraction and quality assessments. Results A narrative review was carried out. Very few studies were identified; only three from Sweden consider CVD outcomes and these are discrepant. There may be a modest association between use of Swedish snuff (snus) and cardiovascular disease (e.g., relative risk = 1.4, 95% confidence interval 1.2–1.6) in one prospective cohort study. Several other studies have considered associations between ST use and intermediate outcomes (CVD risk factors). Conclusions There may be an association between ST use and cardiovascular disease. However, further rigorous studies with adequate sample sizes are required. Eur J Cardiovasc Prevention Rehab 11:101–112

Life-years gained from coronary heart disease mortality reduction in Scotland: Prevention or treatment?

Coronary Heart Disease (CHD) death rates have fallen considerably in many countries. We estimated the life-years-gained (LYG) in Scotland between 1975 and 1994 attributable to cardiology treatments, and population reductions in major CHD risk factors, using a previously validated mortality model. This combines published effectiveness data with information on uptake of CHD treatments; risk factor trends; and median survival by age and sex. Compared with 1975, there were 4,536 fewer CHD deaths in 1994, resulting in approximately 48,016 LYG among those aged 45-84 (maximum estimate 53,317; minimum estimate 36,867). Medical and surgical treatments for CHD patients gained approximately 12,025 life-years; the largest contribution coming from pharmacologic secondary prevention. Population reductions in major risk factors (smoking, cholesterol, and blood pressure) accounted for some 35,991 LYG, reductions in smoking accounted for over 50% of this. Modern cardiologic treatments gained many thousands of life-years in Scotland, but modest reductions in risk factors gained almost three times as many life-years.