Martin Winn's cholesterol level was inching up. Cycling up hills, he felt chest pain that might have been angina. So he and his doctor decided he should be on a cholesterol-lowering medication called a statin. He was in good company. Such drugs are the best-selling medicines in history, used by more than 13 million Americans and an additional 12 million patients around the world, producing $27.8 billion in sales in 2006. Half of that went to Pfizer for its leading statin, Lipitor. Statins certainly performed as they should for Winn, dropping his cholesterol level by 20%. "I assumed I'd get a longer life," says the retired machinist in Vancouver, B.C., now 71. But here the story takes a twist. Winn's doctor, James M. Wright, is no ordinary family physician. A professor at the University of British Columbia, he is also director of the government-funded Therapeutics Initiative, whose purpose is to pore over the data on particular drugs and figure out how well they work. Just as Winn started on his treatment, Wright's team was analyzing evidence from years of trials with statins and not liking what it found.
Yes, Wright saw, the drugs can be life-saving in patients who already have suffered heart attacks, somewhat reducing the chances of a recurrence that could lead to an early death. But Wright had a surprise when he looked at the data for the majority of patients, like Winn, who don't have heart disease. He found no benefit in people over the age of 65, no matter how much their cholesterol declines, and no benefit in women of any age. He did see a small reduction in the number of heart attacks for middle-aged men taking statins in clinical trials. But even for these men, there was no overall reduction in total deaths or illnesses requiring hospitalization -- despite big reductions in "bad" cholesterol. "Most people are taking something with no chance of benefit and a risk of harm," says Wright. Based on the evidence, and the fact that Winn didn't actually have angina, Wright changed his mind about treating him with statins -- and Winn, too, was persuaded. "Because there's no apparent benefit," he says, "I don't take them anymore."
Wait a minute. Americans are bombarded with the message from doctors, companies, and the media that high levels of bad cholesterol are the ticket to an early grave and must be brought down. Statins, the message continues, are the most potent weapons in that struggle. The drugs are thought to be so essential that, according to the official government guidelines from the National Cholesterol Education Program, 40 million Americans should be taking them. Some researchers have even suggested -- half-jokingly -- that the medications should be put in the water supply, like fluoride for teeth. Statins are sold by Merck (Mevacor and Zocor), AstraZeneca (Crestor), and Bristol-Myers Squibb (Pravachol) in addition to Pfizer. And it's almost impossible to avoid reminders from the industry that the drugs are vital. A current TV and newspaper campaign by Pfizer, for instance, stars artificial heart inventor and Lipitor user Dr. Robert Jarvik. The printed ad proclaims that "Lipitor reduces the risk of heart attack by 36%...in patients with multiple risk factors for heart disease."
So how can anyone question the benefits of such a drug?
For one thing, many researchers harbor doubts about the need to drive down cholesterol levels in the first place. Those doubts were strengthened on Jan. 14, when Merck and Schering-Plough revealed results of a trial in which one popular cholesterol-lowering drug, a statin, was fortified by another, Zetia, which operates by a different mechanism. The combination did succeed in forcing down patients' cholesterol further than with just the statin alone. But even with two years of treatment, the further reductions brought no health benefit.
Doing the Math
The second crucial point is hiding in plain sight in Pfizer's own Lipitor newspaper ad. The dramatic 36% figure has an asterisk. Read the smaller type. It says: "That means in a large clinical study, 3% of patients taking a sugar pill or placebo had a heart attack compared to 2% of patients taking Lipitor."
Now do some simple math. The numbers in that sentence mean that for every 100 people in the trial, which lasted 3 1/3 years, three people on placebos and two people on Lipitor had heart attacks. The difference credited to the drug? One fewer heart attack per 100 people. So to spare one person a heart attack, 100 people had to take Lipitor for more than three years. The other 99 got no measurable benefit. Or to put it in terms of a little-known but useful statistic, the number needed to treat (or NNT) for one person to benefit is 100.
Compare that with, say, today's standard antibiotic therapy to eradicate ulcer-causing H. pylori stomach bacteria. The NNT is 1.1. Give the drugs to 11 people, and 10 will be cured.
A low NNT is the sort of effective response many patients expect from the drugs they take. When Wright and others explain to patients without prior heart disease that only 1 in 100 is likely to benefit from taking statins for years, most are astonished. Many, like Winn, choose to opt out.
Plus, there are reasons to believe the overall benefit for many patients is even less than what the NNT score of 100 suggests. That NNT was determined in an industry-sponsored trial using carefully selected patients with multiple risk factors, which include high blood pressure or smoking. In contrast, the only large clinical trial funded by the government, rather than companies, found no statistically significant benefit at all. And because clinical trials themselves suffer from potential biases, results claiming small benefits are always uncertain, says Dr. Nortin M. Hadler, professor of medicine at the University of North Carolina at Chapel Hill and a longtime drug industry critic. "Anything over an NNT of 50 is worse than a lottery ticket; there may be no winners," he argues. Several recent scientific papers peg the NNT for statins at 250 and up for lower-risk patients, even if they take it for five years or more. "What if you put 250 people in a room and told them they would each pay $1,000 a year for a drug they would have to take every day, that many would get diarrhea and muscle pain, and that 249 would have no benefit? And that they could do just as well by exercising? How many would take that?" asks drug industry critic Dr. Jerome R. Hoffman, professor of clinical medicine at the University of California at Los Angeles.
Drug companies and other statin proponents readily concede that the number needed to treat is high. "As you calculated, the NNT does come out to about 100 for this study," said Pfizer representatives in a written response to questions. But statin promoters have several counterarguments. First, they insist that a high NNT doesn't always mean a drug shouldn't be widely used. After all, if millions of people are taking statins, even the small benefit represented by an NNT over 100 would mean thousands of heart attacks are prevented.