spinning data

[Guest guest]

and weaving profits.

M.

****

http://www.knowledgeofhealth.com/report.asp?story=Modern%20medicines%20sleight%20of%20hand & catagory=Conventional%20Medicine,%20Health%20Agencies

6/4/2006

Modern medicine’s sleight of hand

By Bill Sardi

Here are news headlines derived from published studies of four different

types of drugs:

Cholesterol-lowering statin drugs lower the risk for a heart attack

by 30% Tamoxifen, the drug used to treat breast cancer, cuts the number of

cases of breast cancer by 49%. Bevacizumab (Avastin) plus chemotherapy had a 26 percent reduction in

the risk of death (hazard ratio of 0.74). For males, finasteride (Proscar), a drug often used to treat prostate

inflammation, has been shown to reduce risk for prostate cancer by about

25%.

A naïve reader would get the false impression that these drugs will

result in 30 fewer heart attacks per 100 statin drug users, 49 fewer

cases of breast cancer among 100 tamoxifen users, 26 fewer deaths for

every 100 Bevacizumab users and 25 fewer cases of prostate cancer for

every 100 users of finasteride.

In reality, these are only relative numbers. Buried deep in the data for

these clinical studies is the absolute percentage in “hard numbers” of

how many patients in 100 will actually benefit from the drugs. The

absolute risk reduction is far less than what is quoted in the newspaper

headlines or television reports.

A 25% relative risk reduction can be cited when the absolute occurrence

of a disease among patients taking an inactive placebo is 2% versus 1.5%

taking a drug. However, the absolute difference is only 0.5% (1/2 of

one-percent).

For example, if the incidence of a disease is low, like heart attacks,

that only occur among 2 to 4% of adults over a 5year period, then the

number of patients who would have to take a statin drug to prevent one

heart attack would be 1000 to 2000.

Let’s say heart attacks occur among 3% of 1000 patients over 5 years --

that would amount to 30 heart attacks. A 30% relative risk reduction of

30 would be 9 less heart attacks (21 total over 5 years). That’s two

heart attacks that were prevented every year among 1000 statin drug

users, or just 0.2% difference (2/10ths of one percent) between users and

non-users of statin drugs. Some 1,825,000 statin pills would be consumed

to prevent 9 heart attacks – but not 9 lives saved. Statin drugs in the

widely-quoted meta-analysis (review of many studies where statistics are

pooled together) did not reduce all-cause mortality rates. Statin drugs

slightly prevented heart attacks, but not mortal heart attacks.

In the 4 statin drug trials analyzed to come up with the widely-used

figure of a 30% reduction in heart attacks, here is what the hard numbers

looked like: 67 of 7065 (0.948%- 9/10ths of one-percent) statin drug

users died versus 102 of 7054 (1.446% - nearly 1½ of one percent) who did

not take the drug, for an absolute difference of 0.498% (1/2 of one

percent, absolute difference). [british Medical Journal 323: 1-5, 2000]

But cardiologists will look directly into their patients’ eyes and tell

them they may die of a heart attack if they don’t take the drug.

Actually, there is little chance of benefiting from statin drugs, and

more risk of experiencing side effects, like elevated liver enzymes and

muscle degradation, which is a mortal risk in itself.

Another part of the shell game is that the cholesterol studies only

involved high-risk individuals, but the cholesterol drugs are being

prescribed to healthy middle-aged adults. So their chance of benefiting

from the drugs is nil x nil.

Cancer drug deception

The same decption is true for the anti-cancer drug bevacizumab

(Avastin). Only when used with another cancer drug did bevacizumab

increase median survival for colon cancer patients from 15.6 months to

20.3 months, a 4.7 month difference over chemotherapy alone. On a

relative basis, this was a 26 percent reduction in mortality. [New

England Journal of Medicine 350: 2335-2342, 2004]

Tamoxifen shell game

The same shell game is used to promote Tamoxifen, a drug that many

women refuse to take because of its side effects.

The National Cancer Institute (NCI) reports that 10 million American

women are at high risk for breast cancer and maybe ought to see their

doctors about taking tamoxifen. The NCI concedes only 2.4 million women

are likely to benefit from taking the drug, and out of this group of 2.4

million the number of cases of breast cancer is likely to be reduced from

58,148 to 28,492. The number of cases of breast cancer appears to be cut

in half (49 percent) when viewed as a relative percentage.

But in reality, only 2.4 percent of the 2.4 million women would be

expected to develop breast cancer if they didn’t take tamoxifen and 1.2

percent if they did. So the difference in hard numbers is only 1.2

percent. [Journal National Cancer Institute 95: 526-32, 2003]

This is hardly a good way of selling Tamoxifen to American women, so the

relative numbers are used instead. Then it’s called a blockbuster drug.

It’s very misleading. Yes, admittedly when looking at hard numbers about

20,000 additional women would be spared from breast cancer. The problem

is you have to get over 2 million women to take the drug to realize this

benefit.

Another one of the hidden facts about tamoxifen is that half of the women

with advanced estrogen-positive tumors immediately fail to respond to

this drug and are removed from drug therapy. So the studies don’t always

include these failures. [Drugs 61: 1721-33, 2001]

Current efforts to expand tamoxifen therapy as a preventive agent for

breast cancer have begun. High-risk but otherwise healthy women derive

some risk reduction if given tamoxifen. Of the 6600 women who took

tamoxifen, there were 69 fewer tumors compared to 6000 other women who

took a dummy pill. In other words, tamoxifen benefited only about 1 in

100 high-risk women as a preventive measure. Yet it was widely hailed as

a breakthrough! [Associated Press Oct. 30, 1998] There has been

resistance to the idea of giving healthy women a drug that runs the risk

of serious side effects. The National Women’s Health Network asked:

“Does this trial represent disease prevention, or disease

substitution?” [breast Cancer Action, Feb. 26, 1996]

Prostate cancer prevention is illusory

The same ruse is used to promote finasteride (Proscar) for prostate

cancer prevention. Finasteride is reported to reduce risk for prostate

cancer by about 25%. It is estimated that widespread use of finasteride

by adult males would add 300,000 years of life over a 10-year period.

[urological Oncology 22: 362-68, 2004] However, it would cost about $3.4

billion per year and require every male in the U.S. age 55 to 80 years of

age to take the drug, to achieve this aggregate health goal. [Journal

National Cancer Institute 96: 1410-12, 2004]

For a hypothetical group of 1000 sixty-two year old men treated with

finasteride, an increased survival of 140 life-years is forecasted, or a

statistical increase in survival of about a month (0.14 years) per

individual. [Journal Urology 175:934-8, 2006]

Here are the hard numbers for finasteride:

The landmark finasteride prevention study involved 9060 men. Among

the men taking finasteride, 18.4% developed prostate tumors versus 24% in

the placebo group, for a real difference of about 6 in 100 men. This

means, over a 7-year period, for every 100 men taking the drug, 94 would

experience no benefit while 6 would. While most men will develop

cancerous cells in their prostate gland if they live long enough, few die

from it.

In the finasteride study, only 10 men died of prostate cancer, five in

each group taking finasteride or placebo. Men taking finasteride who were

found to have prostate cancer were more likely to have a fast growing

kind, which would be expected to be more deadly. So finasteride may

slightly reduce the risk of prostate cancer, but not dying of prostate

cancer. Men taking finasteride had more erectile dysfunction and loss of

interest in sex, but also had fewer urinary problems. [New England

Journal of Medicine 349:215-224, 2003]

News reporters and health agencies all participate in the

charade

A bigger problem here is that news reporters, many of them physicians

or biology-trained, know the magnified numbers in these drug studies are

hardly worth reporting. They are supposed to be “the fourth estate,” the

guardians of public welfare. News reporters these days appear to be

allied with the pharmaceutical companies in reporting these sham numbers.

When the public is informed of the absolute numbers, they are buried at

the bottom of the news story.

Public health agencies are not a cut above the hype news reporters

either. The National Institutes of Health uses these relative numbers to

announce results from freshly-completed clinical studies. The Food &

Drug Administration uses numbers like these to approve new

drugs.

Even doctors are fooled by the relative numbers. A study of internists

and general practitioners who prescribe cholesterol medications found

they were less likely to prescribe these medications when the benefits

were reported in absolute rather than relative percentages. [british

Medical Journal 309: 761-64, 1994]

In the pharmaceutical world today, illusion prevails. Be wary of news

reports that claim the next blockbuster drug reduces the risk for a

disease by 60 percent. That 60 percent just might be 6/10th of one

percent (1.0% reduced to 0.4% = 60% reduction). Copyright 2006 Bill

Sardi, Knowledge of Health, Inc.

www.knowledgeofhealth.com