- 3806 middle-aged men received cholestyramine or placebo over an average of 7.4 years.
- The absolute reduction in all-cause mortality was 7 percentage points, which corresponds to a number needed to treat of 14.
- In other words, cholestyramine prevented 1 death of every 14 people receiving treatment over 7 years.
Source: Lipid Research Clinics Program. The Lipid Research Clinics Coronary Primary Prevention Trial results. I. Reduction in incidence of coronary heart disease. JAMA. 1984;251(3):351-364
Therefore statins, which lower cholesterol even more are to be advised.
This is what it said:
The Lipid Research Clinics Coronary Primary Prevention Trial (LRC-CPPT), a multicenter, randomized, double-blind study, tested the efficacy of cholesterol lowering in reducing risk of coronary heart disease (CHD) in 3,806 asymptomatic middle-aged men with primary hypercholesterolemia (type II hyperlipoproteinemia).
The treatment group received the bile acid sequestrant cholestyramine resin and the control group received a placebo for an average of 7.4 years.
Both groups followed a moderate cholesterol-lowering diet.
The cholestyramine group experienced average plasma total and low-density lipoprotein cholesterol (LDL-C) reductions of 13.4% and 20.3%, respectively, which were 8.5% and 12.6% greater reductions than those obtained in the placebo group.
The cholestyramine group experienced a 19% reduction in risk (p less than .05) of the primary end point--definite CHD death and/or definite nonfatal myocardial infarction--reflecting a 24% reduction in definite CHD death and a 19% reduction in nonfatal myocardial infarction.
The cumulative seven-year incidence of the primary end point was 7% in the cholestyramine group v 8.6% in the placebo group.
In addition, the incidence rates for new positive exercise tests, angina, and coronary bypass surgery were reduced by 25%, 20%, and 21%, respectively, in the cholestyramine group. The risk of death from all causes was only slightly and not significantly reduced in the cholestyramine group. The magnitude of this decrease (7%) was less than for CHD end points because of a greater number of violent and accidental deaths in the cholestyramine group.
The LRC-CPPT findings show that reducing total cholesterol by lowering LDL-C levels can diminish the incidence of CHD morbidity and mortality in men at high risk for CHD because of raised LDL-C levels. This clinical trial provides strong evidence for a causal role for these lipids in the pathogenesis of CHD
BUT...................................................
" Their statistical analysis of the results implied a 24% reduction in the rate of coronary heart disease in the group taking the drug compared with the placebo group; however, non-heart disease deaths in the drug group increased -- deaths from cancer, stroke, violence and suicide. Even the conclusion that lowering cholesterol reduces heart disease is suspect.Independent researchers who tabulated the results of this study found no significant statistical difference in coronary heart disease death rates between the two groups. However, both the popular press and medical journals touted the LRC-CPPT as the long-sought proof that animal fats are the cause of heart disease …"What really happened, and how LRC-CPPT came to lend further support to the lipid hypothesis was nothing more than another masterful case of statistical manipulation. As Dr. Curtis stated:"After 10 years the number dying from coronary heart disease (CHD) plus those suffering a non-fatal myocardial infarction (NFMI) were totaled for both groups. The total incidence in the cholestyramine group was 7.0% and the control group 8.6%.This small difference of 1.6% was reported as a 19% reduction in death and heart attack by using relative risk reduction (the difference of 1.6% is roughly 19% of 8.6) in place of the less misleading absolute risk reduction (1.6%). Furthermore, this tiny difference was given the designation of "statistically significant" by changing the criteria originally given for determination of significance after the data was in."It is often the case that leaders who want to use the cholesterol agenda use statistics to "prove" their point.
Cholesterol Drug Benefits Perpetuated by Statistical Myths
The LRC-CPPT study was only able to show a meaningful benefit because it focused on relative risk reduction rather than absolute risk reduction. What's the difference? You can find a very simple explanation of relative risk vs. absolute risk at the Annie Appleseed Project web site, but let me sum it up here.
- Relative risk reduction is calculated by dividing the absolute risk reduction by the control event rate
- Absolute risk reduction is the decrease in risk of a treatment in relation to a control treatment
In plain English, here's what that means: let's say you have a study of 200 women, half of whom take a drug and half take a placebo, to examine the effect on breast cancer risk. After five years, two women in the drug group develop breast cancer, compared to four who took the placebo. This data could lead to either of the following headlines, and both would be correct:"New Miracle Drug Cuts Breast Cancer Risk by 50%!""New Drug Results in 2% Drop in Breast Cancer Risk!"How can this be?The Annie Appleseed Project explains:"The headlines represent two different ways to express the same data. The first headline expresses the relative risk reduction — the two women who took the drug (subjects) and developed breast cancer equal half the number (50%) of the four women who took the placebo (controls) and developed breast cancer.The second headline expresses the absolute risk reduction — 2% of the subjects (2 out of 100) who took the drug developed breast cancer and 4% of the controls (4 out of 100) who took the placebo developed breast cancer — an absolute difference of 2% (4% minus 2%)."You can now see why clinical trials, especially those funded by drug companies, will cite relative risk reductions rather than absolute risk reductions, and as a patient you need to be aware that statistics can be easily manipulated.
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