3 Public Health Programs to Reduce Coronary Heart Disease

3.1 Introduction

Coronary heart disease is the largest single cause of death in Australia, claiming some 28 000 lives annually. In addition, there are about 150 000 hospitalisations a year due to coronary heart disease. However, mortality and hospitalisation from the disease would be far higher if there had not been a dramatic drop in its incidence over the last 30 years. All-age mortality rates from coronary heart disease peaked in 1968 and have fallen since by over 60 per cent. Mortality rates for males and females aged 35 to 74 have fallen by two-thirds over the last 30 years. The fall in death rates reflects both lower heart attack rates and improved survival after heart attacks.¹

In this chapter we evaluate the role of public health programs in reducing coronary heart disease. The following sections outline the major public health programs since the mid-1960s that have aimed to reduce coronary heart disease and expenditures on these programs. We then describe the decline in mortality from coronary heart disease and the changes in the major risk factors for the disease that have occurred. There follows an assessment of the extent to which the fall in mortality is due to the changes in risk factors and the extent to which changes in risk factors are due to the public health programs. The last two main sections estimate the benefits of reductions in coronary heart disease and provide an overall evaluation of the public health programs.

3.2 Public Health Programs to Reduce Coronary Heart Disease

Many public health programs aim to reduce coronary heart disease in one way or another. Much of the community health program, work by general practitioners, and advice from the nutrition industry aims to reduce the disease. These programs are supported by major research work into the risk factors for heart disease by public health departments in universities and hospitals. Training in public health is now part of the education programs for doctors, nurses and allied health professionals. There is also a large international research and popular literature on lifestyle health issues (AIHW, 1998).

Table 3.1 shows a summary of public health programs to reduce coronary heart disease from the 1960s to the present based on the national programs promoted by the Commonwealth and the National Heart Foundation (NHF). Inevitably the table is selective. It does not include international findings, state-based programs, or campaigns to reduce tobacco smoking (see Table 2.1). As with anti-tobacco campaigns, programs aiming to reduce coronary heart disease have been many and various, and almost certainly have had a cumulative impact on public education and attitudes.

Table 3.1 Programs to reduce coronary heart disease

Year	Public Health Program
1961	National Heart Foundation (NHF) starts operations. Sets up first cardiac assessment centre.
1964	NHF completes initial survey of need for cardiac surgery in Australia.
1965	NHF-funded research into the care of sufferers from heart attack leads to the concept of intensive coronary care. Ten years later, a study of 4000 patients in 25 hospitals reveals hospital mortality has dropped from 40% to 20%.
1968	NHF starts ‘Heart Week’, annual one-week public awareness campaigns.
1972	NHF initiates research into high blood pressure and atherosclerosis.
1973	Federal government funds start of national community health program.
	Start of NHF Blood Pressure Study. Project ran for 10 years at a total cost of $1.2 million.
1975	NHF runs large scale media campaign to help heart attack victims by teaching the symptoms of heart attack. Mobile education units introduced into the community to train nearly 17,000 people in heart-lung resuscitation techniques.
1976	Life Be In It Campaign. Non-government organisation encouraging recreation and physical activity. Queensland and ACT introduce risk assessment centres where members of the public can obtain heart attack risk assessment.
1977	Beat Heart Attack. Five-year program to reduce death and invalidism from heart attack.
1978	NHF initiates Hunter Valley Heart Attack Study recording every case of heart attack in region.
1979	National Food and Nutrition Program is launched.
	NHF launched next phase of national research project on incidence and effects of high blood pressure. Over 80,000 people were screened in four Australian centres.
1980	NHF begins first nationwide Risk Factor Prevalence Study.
	NHF starts new anti-smoking educational program.
1983	NHF completes data collection for first study of prevalence of risk factors for heart disease in metropolitan centres. Start second Risk Factor Prevalence Study.
	Jump Rope for Heart is launched in primary schools. In next 15 years, over 1.0 million young Australians learn about physical activity and the heart.
	Australian component of 'Multinational Monitoring of Trends and Determinants in Cardiovascular Disease' (MONICA) begins in Newcastle and Perth.
1989	Third NHF Risk Factor Prevalence Study.
	NHF public information campaign on passive smoking: so you think you're a non-smoker.
	Launch of Pick the Tick food approval program to help Australian shoppers make healthier food choices easier choices.
1992-96	Launch of National Women’s Health Program and National Aboriginal Health Strategy
1993	National Food and Nutrition Plan (Phase 1).
1994	Hunter Region Heart Disease Prevention Program Risk Factor Prevalence Study
1995	National Centre for Monitoring Cardiovascular Disease located at the AIHW. Final stages of 10-year study coordinated by World Health Organisation and supported by NHF shows trends and determinants for cardiovascular disease in 40 centres and 27 countries.
1996	NHF launches its first five-year National Education and Health Promotion Strategic Plan. Release of NHMRC Preventative Interventions in Primary Health Care – Cardiovascular Disease and Cancer.
1997	National Food and Nutrition Plan (Phase 2). Commonwealth promotes Active Australia – A National Participation Framework. Commonwealth publishes A Strategic Plan for the Prevention of Overweight and Obesity.
1998	Commonwealth releases A Framework for Action for Physical Activity and Health. NHF develops programs for Aboriginal communities and health workers. The NHF-managed LIPID (Long-term Intervention with Pravastatin in Coronary Disease) study shows that cholesterol-lowering drug, pravastatin, can significantly reduce coronary events, stroke, and mortality.
1999	Outcomes resource kit supplied to Divisions of GPs and their members.

The Commonwealth has promoted public health programs at least since 1973 when it started to finance the national community health program. More recently, the National Public Health Partnership between the Commonwealth, State and Territory governments aims to increase public awareness of risk factors through a range of initiatives. The National Health and Medical Research Council (1996) addressed the major risk factors for coronary heart disease (smoking, high blood pressure, obesity, lack of exercise, diabetes, and high blood cholesterol) and recommended ways to handle these risk factors. The Commonwealth Department of Health and Family Services (DHFS, 1997) developed a strategic plan to prevent obesity. Active Australia is a national initiative to promote regular involvement in physical activity (DHFS, 1998a). The Commonwealth has also developed a national nutrition strategy (DHFS, 1998b). In addition, the Commonwealth has funded 44 projects under the Healthy Seniors Initiative to promote the health and wellbeing of older Australians.

All State and Territory governments have been heavily involved in strategies and projects to improve public health with a special emphasis on reducing coronary heart disease (see AIHW, 1998). These strategies are typically aimed at all sections of the community (doctors, allied health professionals, community health workers, adults and children) and across the whole of each state. Under the heading of nutrition, AIHW (1998) lists 17 current or recent public health programs with a State or Territory base, in addition to three national nutrition campaigns.

General practitioners have an important role in educating the public because of their reputation for knowledge. The Royal Australian College of General Practitioners (RACGP) has recently produced guidelines for preventive services in general practice and practical systems to implement the guidelines (RACGP, 1998a, 1998b). Hypertension is the most common cardiovascular condition managed by doctors. In addition to treating this condition with drugs, doctors generally provide advice about how to reduce the risk factors (Waters et al. 1998).

The National Heart Foundation of Australia (NHF) is the major non-government organisation that promotes cardiovascular health. The NHF has initiated numerous projects including the development of clinical guidelines to assist general practitioners, addressing cardiovascular risk and disease management, education in nutrition of primary school students and promotion of increased physical activity.

3.3 Expenditure on Public Health Programs to Prevent Coronary Heart Disease

There are few data readily available on the costs of public health programs to avert coronary heart disease. These programs are part of the group labelled ‘selected health promotion’ in Table 1.2. Total expenditure on this group by government health portfolios was $188 million in 1998-99.² However, this group of programs includes: healthy settings, nutrition, exercise and physical activity, personal hygiene and obesity, mental health, sun exposure and protection, school health, suicide protection, injury prevention, female genital mutilation, drugs of dependence, and other multi-purpose health promotion. No breakdown of these expenditures is available at the time of writing.

For this study we reviewed the expenditures of the National Heart Foundation (NHF) from 1971 to 1999. In year 2000 dollars, total NHF expenditure rose steadily from around $5 million per annum in the early 1970s to $12 million per annum in the late 1980s. However, in the 1990s, NHF expenditure averaged only about $6 million a year.

For the evaluation below we assume that about one-third of the current expenditures on selected health promotion in Table 1.2 (i.e. $60 million) is associated with programs to reduce risk factors for coronary heart disease. We assume also that governments and the NHF have been spending similar amounts on these programs since the early 1980s and lower amounts in the 1970s (see Table 3.8). These are, and can only be, crude assumptions. However, the estimated benefits of the public health programs are so large that the outcome of the evaluation is not sensitive to large variations in these assumptions.

3.4 The Decline in Mortality from Coronary Heart Disease

Deaths from coronary heart disease in Australia declined from 35 000 a year in the late 1960s to 27 000 a year in the late 1990s. However, these statistics do not convey the real fall in premature deaths in the population mainly at risk, persons aged 35-74 years.³

The number of people aged 35-74 years who died from coronary heart disease declined from 20 057 in 1970 to 9149 in 1998. Over the same period, the number of 35-74 year old people in Australia increased by 80 per cent, from 4.5 million to 8.1 million. To show the real decline in coronary heart disease, the gross mortality statistics must be adjusted for changes in population in the relevant age and sex groups.

For the period 1968 to 1998, Table 3.2 shows the number of deaths from coronary heart disease in males and females aged 35 to 74. It also shows actual mortality rates per 100 000 persons in this age group and the deaths that would have occurred if the mortality rate had remained constant at the 1968 level. For the period 1999 to 2010, Table 3.2 shows the deaths from CHD that would occur with a continuing decline in the mortality rate and those that would occur with a continuation of the 1968 mortality rate.

The following are some key results for males for the period 1968 to 1998.

With an unchanged mortality rate, early deaths for males would have almost doubled from 13 806 to 26 412.
However, the mortality rate fell from 395 per 100 000 males to 84 per 100 000 males.
Actual early deaths halved from 13 806 in 1968 to 6650 in 1998.

The following are some main results for females for the period 1968 to 1998.

With no change in mortality rate, early deaths would have risen from 5905 to 10 689.
However, the mortality rates fell from 118 per 100 000 to 23 per 100 000.
Actual early deaths fell by over 50 per cent from 5905 in 1968 to 2499 in 1998.

Table 3.2 Coronary heart disease deaths for persons aged 35-74


	Males 35-74				Females 35-74
Year	CHD Deaths	Mortality rate/100000	Deaths at 1968 rate	Deaths averted	CHD Deaths	Mortality rate/100000	Deaths at 1968 rate	Deaths averted
1968	13806	395.3	13806	0	5905	117.9	5905	0
1969	13666	388.0	14054	388	5862	112.8	5979	117
1970	13975	379.7	14323	348	6082	114.6	6075	-7
1971	13816	366.7	15046	1230	5980	110.2	6367	387
1972	13803	360.3	15435	1632	5747	104.1	6515	768
1973	13761	350.6	15819	2058	5638	98.8	6682	1044
1974	14005	342.9	16229	2224	5979	107.4	6867	888
1975	13650	327.5	16528	2878	5690	97.3	6977	1287
1976	13658	317.7	16895	3237	5473	90.2	7135	1662
1977	13311	305.4	17243	3932	5387	87.6	7302	1915
1978	12856	285.8	17590	4734	5343	83.2	7491	2148
1979	12578	270.6	17920	5342	5023	75.3	7667	2644
1980	12077	251.7	18282	6205	4851	70.4	7854	3003
1981	12219	243.3	18676	6457	4989	69.8	8074	3085
1982	12052	232.4	19133	7081	4984	67.6	8279	3295
1983	11533	220.4	19546	8013	4887	63.7	8447	3560
1984	11103	204.5	19971	8868	4719	57.4	8621	3902
1985	11185	197.6	20387	9202	4708	55.4	8776	4068
1986	10691	189.3	20868	10177	4673	54.7	8951	4278
1987	10450	174.7	21307	10857	4474	48.6	9111	4637
1988	10218	165.0	21682	11464	4275	44.5	9237	4962
1989	9920	155.3	22073	12153	4150	42.8	9347	5197
1990	9282	142.7	22482	13200	4014	39.0	9479	5465
1991	8775	130.9	22992	14217	3644	34.4	9675	6031
1992	8716	126.6	23497	14781	3622	36.9	9848	6226
1993	8311	115.7	24018	15707	3396	32.6	10034	6638
1994	7975	105.3	24593	16618	3188	29.4	10249	7061
1995	7749	103.3	25027	17278	3028	27.7	10379	7351
1996	7439	97.6	25480	18041	2830	25.9	10499	7669
1997	7131	92.8	25950	18819	2776	25.3	10592	7816
1998	6650	83.8	26412	19762	2499	22.9	10689	8190
Forecast
1999	5497	80.9	26862	21635	2020	22.1	10774	8754
2000	5405	78.1	27356	21951	1972	21.3	10917	8942
2001	5261	75.4	27854	22323	1930	20.6	11046	9116
2003	5244	72.9	28435	23191	1892	19.9	11210	9318
2003	5168	70.4	29021	23853	1854	19.2	11386	9532
2004	5094	67.9	29654	24560	1820	18.5	11596	9776
2005	5035	65.6	30342	25307	1796	17.9	11831	10035
2006	4973	63.3	31058	26085	1771	17.3	12069	10298
2007	4950	61.2	31975	27025	1761	16.7	12429	10668
2008	4922	59.1	32924	28002	1748	16.1	12799	11051
2009	4888	57.0	33900	29012	1747	15.6	13203	11456
2010	4869	55.1	34931	30062	1734	15.0	13626	11892

Source: Annex C.

3.5 Changes in Risk Factors for Coronary Heart Disease

The main risk factors associated with coronary heart disease are obesity, high blood cholesterol, physical inactivity, smoking, high blood pressure and diabetes type 2. In 1995, over 10 million adult Australians (80 per cent of the population) had at least one of these risk factors (Table 3.3).

Despite the high number of Australians with a risk factor in 1995, significant declines in several risk factors, notably in blood pressure, saturated fat intake and smoking, have occurred over the last 20 years (see Tables 3.4 and 3.5). The data on blood cholesterol levels are less clear. Evidence cited by AIHW (1999) suggests that blood cholesterol levels fell only slightly in the 1980s, but studies cited by Taylor (Annex C) suggest that blood cholesterol levels fell significantly over the last 30 years.

On the other hand, there has been little change in physical activity during leisure time and the proportion of people who are overweight or obese has risen sharply.

In this section we describe the data that support these findings and consider the causes of changes in risk factors.⁴

Table 3.3 Adult Australians with a risk factor (1995)

Risk factor	Men	Women
Overweight	4,169,700	3,182,300
High blood cholesterol^a	2,479,700	2,029,400
Physical inactivity	2,260,800	2,399,500
Smoking	1,797,700	1,382,900
High blood pressure	1,112,600	1,079,900
Diabetes type 2	163,000	151,000

(a) Most recent data are for year 1989, for those aged 20-69.

Source: AIHW, 1999, based on 1995 National Health and Nutrition Surveys.

Table 3.4 Changes in risk factors


Risk factor	Unit	Men 1980 1995		Women 1980 1995
People with high blood pressure	%	25	17	17	10
Saturated fat % of total energy intake	%	15.9^a	12.7	16.3^a	12.8
Average blood cholesterol level	Mmol/L	5.72	5.66^b	5.68	5.55^b
People smoking	%	42	30	30	28
People not engaged in physical activity	%	35.6^c	33.5	36.0^c	33.8
People overweight	%	48	63	27	43
People obese	%	8	18	7	16

(a) In 1983

(b) In 1989

Source: AIHW, 1999.

Significant decline in blood pressure

High blood pressure is usually defined as systolic blood pressure greater than or equal to 160 mmHg and/or diastolic blood pressure greater than or equal to 95 mmHg. High blood pressure is a major risk factor for coronary heart disease. It is also associated with high cholesterol levels, physical inactivity, overweight and diabetes.

Based on NHF surveys of risk factors in 1980, 1983, and 1989 and the National Nutrition Survey in 1995, the proportion of the population experiencing high blood pressure fell steadily between 1980 and 1995. In these fifteen years, the proportion of men with high blood pressure fell from 25 per cent to 17 per cent. The proportion of women with high blood pressure fell from 17 per cent to 10 per cent. There was also a significant decline in average blood pressure levels over this period.

Drawing on studies by Dobson (1987), Bennett and Magnus (1994) and Dobson et al. (1999), Taylor estimates that the age-adjusted mean diastolic blood pressure of males fell by over 0.2 mmHg per annum in the 1980s and by over 0.4 mmHg per annum in the 1990s (see Table 3.5). Taylor also estimates that the age-adjusted mean diastolic blood pressure of females fell by over 0.1 mmHg per annum in the 1970s, by over 0.2 mmHg per annum in the 1980s, and by over 0.3 mmHg per annum in the 1990s (Table 3.5).

Significant decline in fat in total energy intake

High intakes of fat, especially saturated fat (for example cheese, butter, milk and meat), are associated with excess blood cholesterol levels, overweight, and increased risk of cardiovascular disease, especially in populations with low physical activity. The NHMRC recommends that total dietary fat should not exceed 30 per cent of total energy intake and that saturated fat should not exceed 10 per cent of total energy intake.

Based on the 1983 National Dietary Survey and the 1995 National Nutrition Survey, total dietary fat intake fell from 37 per cent of total energy intake in the early 1980s to 33 per cent in the mid-1990s. The contribution of saturated fat fell from 16 per cent of total energy intake to 13 per cent.

Decline in level of blood cholesterol

Total blood cholesterol levels above 5.5 mmol/L are an indication of an increased risk of developing coronary heart disease. Levels above 6.5 mmol/L are considered a high risk factor.

Saturated fat is a major cause of elevated cholesterol levels. Cholesterol in other foods also affects cholesterol levels. Heredity is another significant factor in cholesterol levels.

Data from the NHF surveys of risk factors in 1980, 1983, and 1989 suggest that there was only a small decline in the average blood cholesterol level for men and women between 1980 and 1989. There are no national data on cholesterol levels since then.

Table 3.5 Estimated annual changes in mean cholesterol, blood pressure and smoking


Risk factor	Males aged 35-64		Females aged 35-64
	Age-standardised	Age-st. smoothed	Age-standardised	Age-st. smoothed
Diastolic BP (mmHg)
1968-74	0.027	0.070	-0.049	-0.049
1975-79	0.027	-0.047	-0.049	-0.042
1980-84	-0.193	-0.164	-0.027	-0.036
1985-89	-0.273	-0.280	-0.022	-0.029
1990-94	-0.407	-0.397	-0.030	-0.022
1995-99		-0.514		-0.016
Cholesterol (mm/dl)
1968-74	-0.034	-0.032	-0.049	-0.049
1975-79	-0.034	-0.027	-0.049	-0.042
1980-84	-0.013	-0.022	-0.027	-0.036
1985-89	-0.010	-0.017	-0.022	-0.029
1990-94	-0.020	-0.012	-0.030	-0.022
Smoking prevalence (%)
1968-74	-0.345	-0.345	-0.032	-0.032
1975-79	-0.345	-0.345	-0.032	-0.032
1980-84	-0.441	-0.441	0.349	0.349
1985-89	-1.541	-1.541	-0.542	-0.542
1990-94	-0.010	-0.010	-0.161	-0.161
1995-99	-0.010	-0.010	-0.161	-0.161

Source: Taylor (Annex C).

However, the data on saturated fat intake suggests that there was probably a significant decline in cholesterol levels between 1980 and 1995. Drawing on a review of cholesterol levels from 1968 to 1984 by Dobson (1987) and on population surveys in the Hunter region of New South Wales in 1983, 1984 and 1994 (Dobson et al.,1999), Taylor concludes that there were significant reductions in cholesterol levels between 1968 and 1998 (see Table 3.5). The declines for males and females were particularly marked between 1968 and the mid-1980s and were generally higher for females than for males.

Slight increase in physical activity

The US Surgeon General’s Report on Physical Activity and Health (quoted in AIHW, 1999) recommends that 30 minutes of physical activity at a moderate intensity be carried out on most days. Moderate physical activity includes brisk walking, digging in the garden, and cycling.

AIHW (1999) reports that there has been little change in physical activity since the early 1980s. Evidence from the 1989-90 and 1995 National Health Surveys indicates that the proportion of people doing no physical activity during their leisure time fell slightly from just under 36 per cent to just under 34 per cent between 1989-90 and 1995. This fall of about 5 per cent reflected an increase in physical activity among people aged 35-54 years.

Overweight and obesity

A person is considered to be overweight if their bodymass index (weight in kg divided by height in metres squared) is 25 or greater. A person is obese if the index is 30 or more. People who are overweight or obese are at higher risk of coronary heart disease. But it is not known whether this is because of a positive correlation between weight and high blood pressure or between weight and high blood cholesterol or because weight is an independent factor.

Data from three NHF surveys of risk factors in 1980, 1983, and 1989 and the National Nutrition Survey in 1995 indicate that there have been significant and steady increases in the proportions of overweight and obese Australians. The proportion of overweight men aged between 25 and 65 increased from 48 per cent in 1980 to 63 per cent in 1995. The proportion of overweight women similarly aged increased from 27 per cent in 1980 to 43 per cent in 1995

Causes of changes in risk factors

Risk factors can change for several reasons. Analysis of cause and effect is also complicated by the inter-relationships between risk factors. Diet affects blood pressure, cholesterol level and weight. Blood pressure is itself a function of weight and physical activity, as well as other factors such as high intakes of alcohol and salt (in some people) and possibly stress.

In order to estimate the effect of public health programs on risk factors, we also need to estimate what would have happened without the public health programs. It is possible that, without these programs, the population might have grown even more obese! However, this line of thinking is speculative and not pursued here. As we see below, tobacco consumption is an important risk factor for coronary heart disease. The contribution of public health programs to reduced tobacco consumption was assessed in Chapter 2. Thus, the focus here is on the contributions of public health programs to reductions in blood pressure, fat intake and cholesterol levels.

Much of the reduction in blood pressure, especially recently, appears to reflect increased use of drugs that lower blood pressure (and in some cases they also have other useful effects). These drugs include diuretics, beta blockers, calcium blockers, and ACE inhibitors. In the 1990s, overall the daily dose of these drugs increased significantly. Although the use of diuretics (the most common drug used to lower blood pressure in 1990) declined by a third in the 1990s, the use of ACE inhibitors tripled and the use of calcium channel blockers doubled (AIHW, 1998). Also drug effectiveness increased.

Public health programs may have reduced blood pressure via reduction in salt intake, reduction in alcohol intake, or increased physical exercise. However, there is limited evidence of changes in these behaviours. Overall, behavioural changes appear to have had less impact on blood pressure than increased use of more effective drugs.

On the other hand, public health programs have probably been responsible for much of the reduction in fat intake and lower cholesterol levels over the last 30 years. Many campaigns and many health care professional have emphasised the importance of reduced fat intake and lower cholesterol levels. Over most of the period from the late 1960s to the present, changes in diet were the main cause of lower fat intake and cholesterol levels. In recent years, a number of drugs, notably statins (such as simvastatin, pravastatin and fluvastatin), have been introduced that can reduce low-density lipoprotein cholesterol to varying degrees. However, there was little use of these drugs before 1990 and the drugs became widely used only around the mid-1990s.

We conclude that public health programs had a significant impact on tobacco consumption, fat intake, and cholesterol levels, but only a small effect on blood pressure and physical activity. They also appear to have had negligible effect on body weight.⁵ Quantifying the impacts of public health programs on these risk factors, as distinct from the impacts of other socio-economic influences, is very difficult. Even after allowing for the major risk factors of smoking, overweight and physical inactivity, socioeconomic variables (such as income and geography) remain independently associated with the risk of death (Lantz et al. 1998).

In Chapter 2 we allow for the Central Case evaluation that public health campaigns were responsible for 10 per cent of the decline in tobacco reduction. We continue with this assumption in this chapter. We will also assume conservatively that the public health programs were responsible for 20 per cent of the decline in cholesterol levels. Although we examine the impact of lower blood pressure on coronary heart disease below, we do not attribute any of this impact to public health programs. Also, in the absence of evidence that public health programs have reduced obesity or increased exercise, no health benefits are attributed to possible changes in these risk factors. Despite the conservative nature of these assumptions, as we will see, the net benefits of the public health programs are high.

3.6 Changes in Risk Factors and Coronary Heart Disease

What proportions of the declines in CHD mortality rates are attributable to reductions in risk factors? Dobson (1987) estimated that 50 per cent of the decline in male mortality from coronary heart disease (CHD) and 70 per cent of the decline in female mortality from CHD in Australia between 1968 and 1983 were due to declines in tobacco smoking, serum cholesterol and blood pressure. Dobson (1994) estimated that declines in these same factors accounted for 40-66 per cent of declines in CHD mortality for males and 21-53 per cent of declines for females in the 1980s, with the variation depending on the age group.

Similar results have been found in other countries. For example, Hunink et al. (1997) estimated that 55 per cent of the decline in CHD mortality in the United States was due to reduction in risk factors, with 25 per cent due to primary (public health) prevention and 30 per cent due to secondary (medical intervention) prevention. The balance of the decline was due to treatment of coronary heart disease. Capewell et al (2000) concluded that 'approximately half the coronary heart disease mortality fall in Auckland, New Zealand, was attributable to medical therapies and half to reductions in major risk factors'. Other studies give similar results (see Annex C).

For this study, Applied Economics commissioned Dr. Richard Taylor to review the impacts of changes in risk factors on coronary heart disease. Taylor’s report is reproduced in Annex C. The main procedures and findings are described here. In summary, Taylor estimates:

The actual decline in CHD mortality rates by age cohort and sex for persons aged 35 to 74 years from 1968 to 1998 (Table 3.2).
The decline in CHD mortality by age cohort and sex for persons aged 35 to 74 years from 1968 to 1998 that would have occurred if incidence rates had stayed constant at 1968 levels (Table 3.2).
Annual changes in tobacco smoking, serum cholesterol and blood pressure between 1968 and 1998 (Table 3.5 shows some summary estimates). For mean serum cholesterol and mean diastolic blood pressure, the observed changes for five yearly periods were smoothed by linear regression.
The annual reduction in CHD mortality due to changes in tobacco consumption, mean serum cholesterol levels, and diastolic blood pressure. Drawing on MacMahon et al. (1990), Law et al. (1994) and Dobson et al. (1999), Taylor estimates that the coronary heart mortality rate fell by 0.4574 for each reduction in 1 mmol/L in mean serum cholesterol and by 0.0471 for each reduction in 1 mmHg in diastolic blood pressure.
Deaths averted and years of life saved due to the changes in risk factors between 1968 and 1998.
Deaths averted annually up to 2010 due to continuing improvements in risk factors and treatment, based on AIHW (1998) projections of changes in risk factors and treatment.

Table 3.6 shows Taylor’s estimates of deaths averted due to lower blood pressure, cholesterol levels and tobacco smoking, as individual and as combined factors. Because of interactions between the three factors, the combined effects are less than the sum of individual effects. Declines in smoking and cholesterol levels account for an estimated 43 per cent of the fall in CHD mortality rates for males between 1968 and 1998 and for an estimated 41 per cent of the fall in CHD mortality rates for females over the same 30 years. Including declines in blood pressure, the three risk factors accounted for an estimated 57 per cent of lower mortality for males and 55 per cent for females between 1968 and 1998.

As shown in Annex C, the effects of changes in the three risk factors were not constant over time. Declines in serum cholesterol level dominated between 1968 and 1979. Declines in tobacco smoking had the largest impact in the 1980s. Declines in blood pressure were the most important impact in the 1990s.

In 1998, reductions in the three risk factors (blood pressure, cholesterol levels and smoking) averted an estimated 11 294 early male deaths and 4508 early female deaths. The average length of life saved was 11.5 years for males and 8.7 years for females. Over the 42 years period, reductions in these three risk factors averted an estimated 323 824 early male deaths and 133 561 early female deaths.

In the absence of longitudinal data on hospitalisation due to coronary heart disease, we have not estimated the decline in hospitalisations resulting from reduced CHD. However, in the following section we estimate approximate savings in hospital and medical costs that are likely to have occurred because of reduced coronary heart disease.

Table 3.6 Estimated early CHD deaths averted due to lower risk factors

(persons 35-74 years)


Year	Males: lower risk factors					Females: lower risk factors
	Sm.	Chol.	BP	Sm + Chol	All three	Sm.	Chol.	BP	Sm + Chol	All three
1968	0	0	0	0	0	0	0	0	0	0
1969	106	206	-46	309	264	6	133	28	138	165
1970	213	411	-93	614	525	13	265	56	274	327
1971	322	621	-141	924	792	20	399	85	413	492
1972	433	831	-191	1231	1057	27	532	114	550	654
1973	544	1041	-241	1536	1321	33	663	143	686	813
1974	656	1251	-292	1839	1583	41	794	173	821	971
1975	773	1427	-257	2112	1892	48	906	217	937	1121
1976	891	1604	-222	2383	2198	55	1017	262	1053	1270
1977	1009	1780	-186	2652	2500	62	1127	306	1167	1416
1978	1128	1956	-150	2919	2799	69	1237	351	1281	1560
1979	1247	2133	-114	3184	3096	77	1347	396	1395	1703
1980	1409	2278	15	3453	3467	-8	1439	456	1419	1772
1981	1571	2423	146	3721	3834	-96	1532	517	1443	1842
1982	1738	2572	279	3992	4202	-188	1625	579	1467	1913
1983	1906	2723	415	4265	4569	-283	1720	642	1492	1984
1984	2077	2877	553	4539	4935	-381	1815	706	1518	2056
1985	2883	2997	794	5281	5816	-201	1893	787	1728	2305
1986	3668	3119	1038	6000	6659	-20	1971	868	1936	2547
1987	4431	3244	1284	6695	7462	160	2051	950	2142	2785
1988	5174	3370	1533	7366	8229	341	2131	1034	2345	3017
1989	5898	3498	1784	8015	8960	523	2212	1118	2546	3244
1990	5903	3589	2142	8082	9209	578	2275	1220	2643	3391
1991	5908	3682	2502	8149	9458	634	2339	1322	2740	3536
1992	5913	3777	2862	8218	9706	691	2404	1426	2838	3681
1993	5919	3873	3222	8287	9953	749	2469	1530	2936	3824
1994	5925	3970	3584	8358	10198	807	2535	1635	3035	3965
1995	5930	4028	4053	8401	10475	868	2582	1759	3118	4103
1996	5936	4087	4521	8446	10750	930	2630	1883	3201	4239
1997	5942	4147	4987	8491	11023	993	2679	2007	3284	4374
1998	5949	4208	5451	8537	11294	1056	2728	2133	3369	4508
1999	5955	4269	5912	8584	11562	1120	2778	2258	3453	4641
2000	5961	4332	6370	8631	11827	1185	2828	2384	3538	4772
2001	5968	4396	6824	8679	12090	1251	2879	2510	3623	4901
2003	5974	4460	7273	8728	12349	1317	2930	2636	3708	5028
2003	5981	4525	7719	8777	12604	1384	2982	2762	3794	5154
2004	5988	4591	8161	8826	12857	1451	3034	2888	3879	5279
2005	5995	4658	8599	8877	13108	1520	3086	3015	3965	5402
2006	6002	4725	9035	8928	13355	1589	3140	3142	4052	5523
2007	6009	4794	9468	8980	13601	1659	3194	3269	4139	5644
2008	6016	4864	9897	9032	13843	1730	3248	3397	4226	5763
2009	6023	4935	10323	9085	14083	1801	3303	3525	4313	5880
2010	6031	5006	10744	9139	14319	1873	3359	3653	4401	5996

^a Average blood pressure increases in 1970s, so causing an increase in estimated deaths.

Source: Annex C.

3.7 Benefits of Reduced Coronary Heart Disease

In order to estimate the benefits of reduced coronary heart disease due to public health programs, we estimate:

The total cost of the disease in 1996, because estimates of years lost and disability due to CHD are available for that year.
The total benefits associated with the reduction in CHD in 1998 (the same year as was used for tobacco reduction in Chapter 2).
The proportion of these benefits in 1998 attributable to the public health programs.
The benefits in other years (1971 to 2010) attributable to the public health programs.

As discussed previously, the three main benefits from improved health are longevity, improved health status, and reduced health care expenditures. Table 3.7 shows estimated disability-adjusted life years (DALYs) from coronary heart disease in 1996. This is the sum of estimated years of life lost due to early death and equivalent years lost due to disability, based on Mathers et al. (1999).⁶ There were an estimated 311 000 DALYs due to coronary heart disease in 1996. Of these DALYs, 89 per cent were attributable to premature death and 11 per cent were due to disability.

Table 3.7 Estimated DALYs due to coronary heart disease in 1996 (all ages)

Deaths and DALYs	Male	Female	Total
Deaths	17,263	15,418	32,681
Years of life lost due to early death	158,378	117,399	275,778
Equivalent years lost due to disability	22,252	13,300	35,552
Total DALYs	180,630	130,699	311,330

Source: Mathers et al., 1999.

Mathers et al (1999) estimated that death due to coronary heart disease causes an average of 8.5 years loss of life (this is an all-age average). The present value of $60 000 per annum⁷ for 8.5 years discounted at 5 per cent per annum equals about $400 000 or $50 000 per annum. Using this discounted annual figure of $50 000, the present value of total DALYs lost due to coronary heart disease in 1996 was $15.6 billion.

In addition, health care expenditures on coronary heart disease in 1996 were about $1.0 billion in 1996, in year 2000 dollars.⁸ This is equivalent to about $6500 per hospitalisation for coronary heart disease, inclusive of all medical, drug and other costs.

Thus the estimated total cost of actual coronary heart disease in 1996 was $16.6 billion, made up of $15.6 billion in loss of life and health and $1.0 billion in health care expenditures.

As shown in Table 3.2, if CHD mortality rates had stayed unchanged at 1968 levels, there would have been an estimated additional 28 000 early deaths from CHD in 1998. Reductions in smoking, cholesterol levels and blood pressure were responsible for an estimated fall of nearly 16 000 of these early deaths with an average saving of about 10 years of life.⁹

Allowing a present value of $460 000 for these 10 years of life gained, the benefit from deaths averted in 1998 due to lower risk factors was $7.4 billion. Allowing an extra 13 per cent for the improved health status of those who avoided a poor heart condition (in proportion to the DALYs shown in Table 3.7) adds another $1.0 billion to the estimated health benefits. In addition, health care expenditures would presumably have been some 50 per cent higher without the improvement in the risk factors.¹⁰ There were therefore health care savings of some $0.5 billion.

It follows that the estimated total benefit of the reduction in coronary heart disease in 1998 due to the decline in smoking, cholesterol levels and blood pressure was $8.9 billion. Of these benefits, approximately 83 per cent are years of life gained, 11 per cent are improved quality of life, and 6 per cent are savings in health care expenditures.

In order to evaluate the public health programs, 20 per cent of the cholesterol deaths averted and 10 per cent of the smoking-related deaths averted are attributed to the programs (see Section 3.5). Allowing that lower cholesterol and smoking averted 12 000 early deaths (male plus female) and that approximately half were due to lower cholesterol and half to lower smoking, the public health programs averted approximately 1800 early deaths due to coronary heart diseases in 1998. Allowing a present value of $460 000 for ten years of life gained, the benefit from deaths averted in 1998 due to the public health campaigns was $828 million. Adding 20 per cent for improved health status and lower health care costs, the estimated benefit of the public health campaigns totalled $994 million in 1998. This includes $106 million from improved health status, and $60 million in reduced health care expenditures.

3.8 Evaluation of Public Health Programs to Reduce Coronary Heart Disease

The evaluation of public health campaigns aiming to reduce coronary heart disease covers the period 1971 to 2010. The main results are shown in Table 3.8. The estimated costs of public health programs are based on the discussion in Section 3.3.

As estimated above, the benefits of the public health campaigns totalled $994 million in 1998. For the evaluation, these benefits are projected back to 1971 and forward to 2010 proportionately with deaths averted as shown in Table 3.6 using a similar approach to that adopted for tobacco reduction. Thus the estimated total benefit in any year, say 1990, equals the estimated dollar benefit in 1998 times (deaths averted in 1990 / deaths averted in 1998).¹¹

Using a 5 per cent discount rate, the present value of the costs of the public health programs in year 2000 dollars discounted back to 1971 is $810 million. The estimated benefits are $9289 million. The net benefits are therefore $8478 million. The estimated benefit-cost ratio is over 11:1.

Table 3.8 Evaluation of public health programs to reduce coronary heart disease ($m 2000 $s)^a


Year	Costs	Central case		Sensitivity test
		Benefits	Net benefits	Benefits	Net benefits
1971	30.0	0.0	-30.0	0.0	-30.0
1972	30.0	50.0	20.0	12.5	-17.5
1973	30.0	100.0	70.0	25.0	-5.0
1974	30.0	150.0	120.0	37.5	7.5
1975	30.0	233.4	203.4	58.4	28.4
1976	33.0	268.0	235.0	67.0	34.0
1977	36.0	303.0	267.0	75.8	39.8
1978	39.0	338.0	299.0	84.5	45.5
1979	42.0	373.0	331.0	93.3	51.3
1980	45.0	409.7	364.7	102.4	57.4
1981	48.0	446.0	398.0	111.5	63.5
1982	51.0	481.0	430.0	120.3	69.3
1983	54.0	517.0	463.0	129.3	75.3
1984	57.0	553.0	496.0	138.3	81.3
1985	60.0	589.4	529.4	147.3	87.3
1986	60.0	653.0	593.0	163.3	103.3
1987	60.0	717.0	657.0	179.3	119.3
1988	60.0	780.0	720.0	195.0	135.0
1989	60.0	845.0	785.0	211.3	151.3
1990	60.0	901.8	841.8	225.5	165.5
1991	60.0	915.0	855.0	228.8	168.8
1992	60.0	928.0	868.0	232.0	172.0
1993	60.0	941.0	881.0	235.3	175.3
1994	60.0	954.0	894.0	238.5	178.5
1995	60.0	968.6	908.6	242.2	182.2
1996	60.0	977.0	917.0	244.3	184.3
1997	60.0	986.0	926.0	246.5	186.5
1998	60.0	994.0	934.0	248.5	188.5
1999	60.0	1009.0	949.0	252.3	192.3
2000	60.0	1023.3	963.3	255.8	195.8
2001	60.0	1034.0	974.0	258.5	198.5
2002	60.0	1045.0	985.0	261.3	201.3
2003	60.0	1056.0	996.0	264.0	204.0
2004	60.0	1068.0	1008.0	267.0	207.0
2005	60.0	1079.9	1019.9	270.0	210.0
2006	60.0	1090.0	1030.0	272.5	212.5
2007	60.0	1102.0	1042.0	275.5	215.5
2008	60.0	1114.0	1054.0	278.5	218.5
2009	60.0	1126.0	1066.0	281.5	221.5
2010	60.0	1138.5	1078.5	284.6	224.6

NPV @ 5%	810.7	9289.0	8478.3	2322.3	1511.6
NPV @ 3%	1144.8	14207.6	13062.8	3551.9	2407.1
NPV @ 7%	601.0	6338.7	5737.7	1584.7	983.7

^a Including impact of reduced tobacco consumption on coronary heart disease.

Sensitivity tests

With an estimated net present value of $8478 million and a benefit-cost ratio of over 11:1, the finding that the public health programs provided a major net social benefit is clearly robust and cannot be altered by realistic changes in the assumptions. In any case, for the most part, the report has adopted conservative assumptions.

As a sensitivity test, we examine the scenario that the health benefits were half those estimated by Taylor in Annex C and that the public health programs were half as effective as assumed in the Central Case, i.e. the benefits were 25 per cent of those in the Central Case. In this sensitivity test, the present value of the gross benefits is $2,322 million and the present value of the net benefits is $1,511million. Even on the most conservative assumptions, the net benefit of the public health programs to improve coronary health is large.

On the other hand, if benefits and costs are not discounted, the total benefits rise to $29.2 billion and the costs to $2.1 billion, so that the net benefits would be $27.1 billion.

Financial benefits to government

The estimated saving in health care expenditures due to the public health programs is about 6.0 per cent of total benefits. Using a 5 per cent discount rate, the present value of the savings in health care expenditures would be $557 billion. This is less than the present value of the estimated costs ($810 million). Thus it is possible that the government spent more on the public health programs to reduce CHD than it saved in health care costs. However, it should be noted that the estimates of government expenditures and savings are very approximate. In any case, this does not alter the overall social benefit of the programs.

3.9 Conclusions

Mortality rates from coronary heart disease have fallen substantially over the last 30 years. Mortality rates for males aged 35 to 74 years has fallen from nearly 400 per 100 000 in 1968 to less than 100 per 100 000 in 1998. Mortality rates for females aged 35 to 74 years fell from 118 per 100 000 to 23 per 100 000 over the same period. As a result, there were 28 000 fewer deaths from coronary heart disease than would have occurred with unchanged mortality rates.

Over these 30 years, there were significant declines in some major risk factors for coronary heart disease, namely for smoking, cholesterol, and blood pressure. Changes in these three risk factors accounted for an estimated 70 per cent of the decline in mortality. On the other hand, there was little change in the amount of physical exercise taken and the proportion of overweight persons increased.

Concurrently the Commonwealth and State governments ran numerous media and other information programs, aimed directly at the public or indirectly though GPs. However, there were also other sources of information and drugs contributed substantially to the reduction in blood pressure. This study allows that the public health campaigns were responsible for 10 per cent of the reduction in smoking (as in Chapter 2) and for 20 per cent of the reduction in cholesterol. However, none of the reduction in blood pressure is attributed to the public health campaigns.

The estimated total benefit of reduced coronary heart disease in 1996 due to the three lower risk factors was $8.9 billion, including the benefits from reduced smoking. However, the estimated benefits attributable to public health campaigns were $994 million. This is composed of longevity gains of $828 million, $100 million from improved health status, and $66 million in lower health care costs.

For our 'Central Case' evaluation of the public health programs, the estimated present value of the costs of the public health programs in year 2000 dollars discounted back to 1971 is $810 million. The estimated benefits are $9289 million. The net benefits are therefore $8478 million.

For a sensitivity test, we discounted the benefits attributable to the public health campaigns by 75 per cent. However, even on these most conservative assumptions, the gross benefits of the campaigns total $2151 million and the net benefit would be $1975 million.

In terms of public finances, the present value of the expenditure savings for government in the Central Case would be $557 million. This was probably slightly less than the public cost of the public health programs. However, the cost estimates are very approximate. Moreover, as has been noted, these expenditure savings are only a small part of the total benefit of the public health programs.

¹ The basic data on coronary health can be found in AIHW (1999).

² Expenditure by NGOs and non-health government departments was not collected for 1998/99.

³ The data quoted here were provided by AIHW. See Annex C for details.

⁴ Many of the statistics in this section are from AIHW (1999), Heart, Stroke and Vascular Diseases, Australian Facts.

⁵ As noted, body weight may have been even greater, and physical activity less, without the public health programs.

⁶ In order to obtain years lost due to disability, Mathers et al. use the following disability weights for coronary heart disease: 0.178 for angina, 0.353 for heart failure and 0.395 for acute myocardial infarction.

⁷ See Chapter 1 for the derivation of this figure.

⁸ Estimated health system costs for coronary heart disease totaled $894 million in 1993-94 in then current dollars (Mathers and Penm, 1999). This total included $574 million for hospitals, $86 million for medical care, $105 million for pharmaceuticals, and $127 million for other expenditures.

⁹ This is a rounded average of years saved for males and females aged 35-74.

¹⁰ Premature CHD deaths avoided (16 000) were 57 per cent of actual CHD deaths (28 000) in 1998.

¹¹ The projections are based on five yearly estimates (for 1975, 1980, 1985 and so on) with the intermediate results interpolated.

Applied Economics