Why Almost Everything You Hear About Medicine Is Wrong

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Why Almost Everything You Hear About Medicine Is Wrong

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If you follow the news about health research, you risk whiplash. First

garlic lowers bad cholesterol, then—after more study—it doesn’t. Hormone

replacement reduces the risk of heart disease in postmenopausal women,

until a huge study finds that it doesn’t (and that it raises the risk of

breast cancer to boot). Eating a big breakfast cuts your total daily

calories, or not—as a study released last week finds. Yet even if

biomedical research can be a fickle guide, we rely on it.

But what if wrong answers aren’t the exception but the rule? More and

more scholars who scrutinize health research are now making that claim.

It isn’t just an individual study here and there that’s flawed, they

charge. Instead, the very framework of medical investigation may be

off-kilter, leading time and again to findings that are at best unproved

and at worst dangerously wrong. The result is a system that leads

patients and physicians astray—spurring often costly regimens that won’t

help and may even harm you.

Joe Raedle / Getty Images

Gallery: Medical Breakthroughs: The Good and the Bad

Breakthroughs and Breakdown

It’s a disturbing view, with huge im-plications for doctors,

policymakers, and health-conscious consumers. And one of its foremost

advocates, Dr. P.A. Ioannidis, has just ascended to a new,

prominent platform after years of crusading against the baseless health

and medical claims. As the new chief of Stanford University’s Prevention

Research Center, Ioannidis is cementing his role as one of medicine’s

top mythbusters. “People are being hurt and even dying” because of false

medical claims, he says: not quackery, but errors in medical research.

This is Ioannidis’s moment. As medical costs hamper the economy and

impede deficit-reduction efforts, policymakers and businesses are

desperate to cut them without lowering sacrificing sick people. One

no-brainer solution is to use and pay for only treatments that work. But

if Ioannidis is right, most biomedical studies are wrong.

In just the last two months, two pillars of preventive medicine fell. A

major study concluded there’s no good evidence that statins (drugs like

Lipitor and Crestor) help people with no history of heart disease. The

study, by the Cochrane Collaboration, a global consortium of biomedical

experts, was based on an evaluation of 14 individual trials with 34,272

patients. Cost of statins: more than $20 billion per year, of which half

may be unnecessary. (Pfizer, which makes Lipitor, responds in part that

“managing cardiovascular disease risk factors is complicated”). In

November a panel of the Institute of Medicine concluded that having a

blood test for vitamin D is pointless: almost everyone has enough D for

bone health (20 nanograms per milliliter) without taking supplements or

calcium pills. Cost of vitamin D: $425 million per year.

Ioannidis, 45, didn’t set out to slay medical myths. A child prodigy (he

was calculating decimals at age 3 and wrote a book of poetry at 8), he

graduated first in his class from the University of Athens Medical

School, did a residency at Harvard, oversaw AIDS clinical trials at the

National Institutes of Health in the mid-1990s, and chaired the

department of epidemiology at Greece’s University of Ioannina School of

Medicine. But at NIH Ioannidis had an epiphany. “Positive” drug trials,

which find that a treatment is effective, and “negative” trials, in

which a drug fails, take the same amount of time to conduct. “But

negative trials took an extra two to four years to be published,” he

noticed. “Negative results sit in a file drawer, or the trial keeps

going in hopes the results turn positive.” With billions of dollars on

the line, companies are loath to declare a new drug ineffective. As a

result of the lag in publishing negative studies, patients receive a

treatment that is actually ineffective. That made Ioannidis wonder, how

many biomedical studies are wrong?

His answer, in a 2005 paper: “the majority.” From clinical trials of new

drugs to cutting-edge genetics, biomedical research is riddled with

incorrect findings, he argued. Ioannidis deployed an abstruse

mathematical argument to prove this, which some critics have questioned.

“I do agree that many claims are far more tenuous than is generally

appreciated, but to ‘prove’ that most are false, in all areas of

medicine, one needs a different statistical model and more empirical

evidence that Ioannidis uses,” says biostatistician Goodman of

s Hopkins, who worries that the most-research-is-wrong claim “could

promote an unhealthy skepticism about medical research, which is being

used to fuel anti-science fervor.”

Even a cursory glance at medical journals shows that once heralded

studies keep falling by the wayside. Two 1993 studies concluded that

vitamin E prevents cardiovascular disease; that claim was overturned by

more rigorous experiments, in 1996 and 2000. A 1996 study concluding

that estrogen therapy reduces older women’s risk of Alzheimer’s was

overturned in 2004. Numerous studies concluding that popular

antidepressants work by altering brain chemistry have now been

contradicted (the drugs help with mild and moderate depression, when

they work at all, through a placebo effect), as has research claiming

that early cancer detection (through, say, PSA tests) invariably saves

lives. The list goes on.

Despite the explosive nature of his charges, Ioannidis has collaborated

with some 1,500 other scientists, and Stanford, epitome of the

establishment, hired him in August to run the preventive-medicine

center. “The core of medicine is getting evidence that guides decision

making for patients and doctors,” says Ralph Horwitz, chairman of the

department of medicine at Stanford. “ has been the foremost

innovative thinker about biomedical evidence, so he was a natural for us.”

Ioannidis’s first targets were shoddy statistics used in early genome

studies. Scientists would test one or a few genes at a time for links to

virtually every disease they could think of. That just about ensured

they would get “hits” by chance alone. When he began marching through

the genetics literature, it was like Sherman laying waste to Georgia:

most of these candidate genes could not be verified. The claim that

variants of the vitamin D–receptor gene explain three quarters of the

risk of osteoporosis? Wrong, he and colleagues proved in 2006: the

variants have no effect on osteoporosis. That scores of genes identified

by the National Human Genome Research Institute can be used to predict

cardiovascular disease? No (2009). That six gene variants raise the risk

of Parkinson’s disease? No (2010). Yet claims that gene X raises the

risk of disease Y contaminate the scientific literature, affecting

personal health decisions and sustaining the personal genome-testing

industry.

Statistical flukes also plague epidemiology, in which researchers look

for links between health and the environment, including how people

behave and what they eat. A study might ask whether coffee raises the

risk of joint pain, or headaches, or gallbladder disease, or hundreds of

other ills. “When you do thousands of tests, statistics says you’ll have

some false winners,” says Ioannidis. Drug companies make a mint on such

dicey statistics. By testing an approved drug for other uses, they get

hits by chance, “and doctors use that as the basis to prescribe the drug

for this new use. I think that’s wrong.” Even when a claim is disproved,

it hangs around like a deadbeat renter you can’t evict. Years after the

claim that vitamin E prevents heart disease had been overturned, half

the scientific papers mentioning it cast it as true, Ioannidis found in

2007.

The situation isn’t hopeless. Geneticists have mostly mended their ways,

tightening statistical criteria, but other fields still need to clean

house, Ioannidis says. Surgical practices, for instance, have not been

tested to nearly the extent that medications have. “I wouldn’t be

surprised if a large proportion of surgical practice is based on thin

air, and [claims for effectiveness] would evaporate if we studied them

closely,” Ioannidis says. That would also save billions of dollars.

Lundberg, former editor of The Journal of the American Medical

Association, estimates that strictly applying criteria like Ioannidis

pushes would save $700 billion to $1 trillion a year in U.S. health-care

spending.

Of course, not all conventional health wisdom is wrong. Smoking kills,

being morbidly obese or severely underweight makes you more likely to

die before your time, processed meat raises the risk of some cancers,

and controlling blood pressure reduces the risk of stroke. The upshot

for consumers: medical wisdom that has stood the test of time—and large,

randomized, controlled trials—is more likely to be right than the latest

news flash about a single food or drug.

http://www.newsweek.com/2011/01/23/why-almost-everything-you-hear-about-medicine\

-is-wrong.html