Monday, May 28, 2007

Diabetes scare -- again over a tiny risk

Post lifted from New Editor. See the original for links

My father takes Avandia for his diabetes, so naturally I was a little alarmed when I saw the USA Today headline: Diabetes Drug Called Heart Death Risk. But one must turn to page 2 of the print version to get to the pertinent facts.

Taken together, the studies involved more than 27,000 patients. There were 86 heart attacks and 39 deaths from heart disease among Avandia patients; there were 72 heart attacks and 22 deaths among patients not taking the drug.

The story makes it sound as if GlaxoSmithkline were trying to cover up the risks, when in reality the test results were available on a website the company set up for the purpose of disclosure. The USA Today writer calls the website "obscure," showing obvious anti-corporate bias. Government officials are doing the "who knew what when" thing, as if 17 deaths in 27,000 diabetes-afflicted people is cause for government action.

It's true that 39 deaths instead of 22 is a 64% increase. But 17 deaths out of 27,000 is .0006, or 6 hundredths of one percent. That's barely within statistical significance.

Vioxx was taken off the market for an elevated risk that was fairly tiny compared to the number of people taking it, and by all accounts, suffering from arthritis pain much less because of it.

3.5% of the subjects on Vioxx had suffered a heart attack or stroke, compared with 1.9% on placebo

Merck volutarily took Vioxx off the market. But USA Today ran a story that makes Merck seem shadowy, marketing relentlessly while withholding information about danger. But anyone on Vioxx would tell you about how it made their daily life less painful.

Marjorie Chepp of Milwaukee had been taking Vioxx for nearly two years. Her doctor first prescribed it for a knee injury, but Chepp found that it also relieved her osteoarthritis and fibromyalgia. She asked to remain on it.

Why, in a free country, can't adults in consulation with their doctor make an educated risk decision about a drug that works?

Scientific fraud

Replication is the only test of truth and I myself repeatedly assist those who wish to replicate my research findings

You have to wonder at some people. I have been wondering at Jon Sudbo, a Norwegian scientist who published a paper in The Lancet in 2005 showing that a certain class of painkillers cut the risk of oral cancer. Sudbo, it turned out, made the whole lot up. And he was astoundingly dim in the way he went about inventing his 908 patients: he gave 250 the same date of birth.

As I learnt at a terrific conference in London last week, hosted by the charity Fraud Advisory Panel, there are many more Sudbos out there but scant means of spotting them. The handful who are found must be a tiny minority, said Philip Campbell, editor-in-chief of Nature. And so, he says, we need to consider "going the extra mile" to find them. He is considering whether some studies, especially ones that make headlines, should be replicated before going to press.

Science operates on an assumption of honesty - raw data are rarely scrutinised by either institutions or journals, and academics are encouraged to work independently. Rogue researchers feed off this culture of trust: busy superiors and colleagues often sign off research papers and grant applications without reading them. Fame ensues and grants and citations roll in. And so it becomes hard to "out" a suspect. Do you snitch to your head of department, for example? To your vice-chancellor? Might he or she wish to conceal an issue that could make the institution look culpable? If the person moves and you divulge your suspicions to his new employer, can you be sued?

One solution is to make whistleblowing easier. On Friday the Research Integrity Office, a panel set up last year to promote good practice in biomedical research, launched a confidential hotline for the reporting of misconduct in universities, industry and the NHS (0844 7700644). About 1 per cent of clinical trials are thought to be suspect. This can distort the literature and put patients at risk.

It is a useful step but a modest one: it does not deal with bad behaviour in the physical sciences. And the onus is still on the host institution to investigate and punish. As Dr Campbell told me, some institutions take this responsibility more seriously than others. Woo Suk Hwang, the South Korean biologist who falsely claimed to have cloned a human embryo and extracted embryonic stem cells from it, was brought down chiefly by his own university. Others close ranks.

The conference brought a provocative contribution from Nicholas Steneck, a scientific fraudbuster from the University of Michigan, who pointed out that while plagiarism is undesirable, it may do less harm than the commoner practice of altering data analysis methods to achieve a desired result [See the righthand column of this blog for MY comment on the statistical analyses characteristic of medical research]. Professor Steneck asked: "What does plagiarism do to the literature? Not very much - as long as the plagiariser is accurate." And provided, of course, that the person whose work you're copying has higher standards of integrity than you.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


1 comment:

Bob said...

A big Mac meal has a salad? I thought it was just a burger, fries and a shake?