Nutrition and Coronary Heart Disease
Table C-3 and Table C-4 show the changes in death rates if the corresponding strategy results in the
same reductions in the SWSAHS as they achieved in the literature. In other words, the reduction
in CHD deaths (usually measured in per 100,000 population). The footnotes provide a detailed
account of the source, the methodology used and any necessary assumptions that this analysis has
had to make.
Table C- 3: Effectiveness measures
|
Strategy |
Target |
Existing CHD |
New CHD death rate per | ||
|
death rate per |
100,000, if strategy | ||||
|
100,000 |
implemented.* | ||||
|
GP |
High risk individuals |
Male |
Female |
Male |
Female |
|
Obese |
27O20 |
1162° |
13520 |
5820 | |
|
Inadequate physical |
25721 |
HO21 |
19821 |
8221 | |
|
activity | |||||
|
High cholesterol |
27722 |
11522 |
23522 |
9822 | |
|
Very high cholesterol |
39622 |
16422 |
33722 |
13922 | |
|
Hypertension |
36123 |
14923 |
31023 |
12823 | |
*note: the ‘new CHD death rate’ does not necessarily apply to the entire sub-group, but only to
those who have succeeded in changing their risk factors. A more detailed explanation of this
appears below.
20 Geppert, J & Splett, P. ‘Summary document of nutrition intervention in obesity’., Journal of the American Dietetic Association,
Nov 1991 Supplement, Vol 91, No. 11; S31-5.
Obesity is a very difficult risk factor to assess. Firstly, the risk to CHD is well established but the actual level of risk is often
disputed. Secondly, the effectiveness measure of different weight loss programs show conflicting results. This analysis has used
evidence that suggests that approximately 5-10 % of people who enter a weight loss program can lose 12 kilos. Calculatingfhe
effectiveness of the program we took the mid-point (7.5%) of the total number of obese people in SWS and reduced their respective
CHD death rate to the overall death rate. For the remaining 92.5% of obese people, the CHD death rate remains the same.
21 Mant, D and Little, P 1996, ‘Exercise’ in Lawrence et al (ed), Prevention of Cardiovascular Disease; an evidence based approach.,
Oxford Medical Publications, 1996.
Loughlan & Mutrie., An Evaluation of the Effectiveness of Three Interventions in Promoting Physical Activity in a Sedentary
Population., Health Education Journal (1997)., 56, 154-156.
Exercise programs have a highly variable success rate. The approach we took here is that the program is successful in changing the
exercise behaviour of 20% of individuals who lead a sedentary lifestyle. For those 20% the CHD death rate reverts to the general
population rate, whilst for the remaining 80% the CHD death rate stays at the old level.
22 Tang et al., ‘Systematic Review OfDietary Intervention Trials to Lower Blood Cholesterol in Free-living Subjects’, BMJ
1998;316:1213-1220.
Keyserling et al 1997, ‘RCT of a Physician Directed Treatment Program for Low-Income Patients with High Blood Cholesterol: The
Southeast Cholesterol Project’, Archives of Family Medicine-, 6:135-145
Evidence suggests that for every 0.6mmol∕l reduction in cholesterol there is a 50% reduction of CHD for 40 year olds and a 20%
reduction in risk for 70 year olds. This paper adjusted this for the age profile of the SWSAHS and used the available evidence from
Tang et al on the actual expected reduction in cholesterol.
23 Stamler et al. 1989, ‘Blood Pressure and Risk of Fatal CHD’, Hypertension-, 13(suppl 1): 12 -112.
Law & Wald. 1991, ‘By how much does dietary salt reduction lower blood pressure?’ BMJ;302:811-815.
Several studies consistently show encouraging results in reducing both the incidence Ofhypertension as well as the reduction of
average blood pressure levels amongst these high-risk individuals. This analysis used figure that a “reduced-salt’ diet will result in
an average drop of 5-7 mm Hg in both systolic and diastolic blood pressure. This figure will result in reducing the risk of CHD
deaths by 14%.
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