Statins and the number needed to treat

“Do Cholesterol Drugs Do Any Good?” by John Carey. Business Week, 17 January 2008.

I stumbled across this article earlier this week and was intrigued. My bus driver, who I found out last month studies and gives seminars on nutrition, spoke disparagingly about statins, and then I talked at length with a relative over spring break about the medications he takes. I also carry a torch for LDL cholesterol levels insofar as I think it bears too much of the blame for heart disease.

This article focuses on a statistic I’d never heard of before: number needed to treat, or NNT. NNT is the number of people that need to be treated in order for one person to benefit, compared to a control. The lower the NNT, the more effective the treatment. Lipitor’s newspaper ad says in large print "Lipitor reduces the risk of heart attack by 36%...in patients with multiple risk factors for heart disease" and in small print, "3% of patients taking a sugar pill or placebo had a heart attack compared to 2% of patients taking Lipitor." That yields a NNT of 100 as calculated below:

1/(experimental event rate – control event rate) = 1/(0.03-0.02) = 100

This means that you need to treat 100 people with statins in order for one person to benefit. Corey cites the example of the standard antibiotic treatment for H. pylori stomach bacteria, which cause ulcers. Its NNT is 1.1 – treat 11 people and 10 will be cured.

Statins’ high NNT means different things for an individual and a population, according to Dr. Peter Trewby, consultant physician at Darlington Memorial Hospital in Britain.

"It's all about whether we think the population is what matters, in which case we should all be on statins, or the individual, in which case we should not be…What is of great value to the population can be of little benefit to the individual."

The drug companies sure would enjoy having everyone with elevated cholesterol taking a statin. But statins are not cheap or free from side effects. And they only target one parameter, unlike diet and exercise, which can have a positive effect on a number of health indicators.

Cholesterol is handy because it’s relatively easy to measure and track. But it’s just one number. We are assessing our iron status in Experimental Nutrition and are measuring five different parameters in order to get a complete picture. And that’s just for iron. Coronary disease is much more complex and has other risk factors besides elevated LDL-cholesterol levels. So focusing on one number is not a very effective mode of treatment.

That’s not to say that we should ignore LDL cholesterol entirely.

Dr. Ronald M. Krauss, director of atherosclerosis research at the Oakland Research Institute, explains that higher LDL levels do help set the stage for heart disease by contributing to the buildup of plaque in arteries. But something else has to happen before people get heart disease. "When you look at patients with heart disease, their cholesterol levels are not that [much] higher than those without heart disease," he says. Compare countries, for example. Spaniards have LDL levels similar to Americans', but less than half the rate of heart disease. The Swiss have even higher cholesterol levels, but their rates of heart disease are also lower. Australian aborigines have low cholesterol but high rates of heart disease.

The article goes on to explain some biochemistry details that I found interesting. I think need to read more about what statins do. Corey’s layman explanation is that they “work by bollixing up the production of a substance that gets turned into cholesterol.” I can do better than that.

Photo and article found here.

One man's stiff shoulder

The Healing of America: A Global Quest for Better, Cheaper, and Fairer Healthcare, by T.J. Reid (Penguin Press, 2009).

I needed a break from reading about the food system. I got tired of reading about how badly school lunch fails, about the size of the average manure lagoon is, etc. I needed new topic.

Health care fit the bill. I guessed that a rundown of the U.S. health care system would be as disheartening as the rundowns of the U.S. food system, but at least it would be new material. I heard an interview with Reid on NPR this summer and the next time his book came onto my radar, I was primed to read it.

Here’s the premise. Journalist T. J Reid took his stiff shoulder to seven industrialized countries to assess their health care systems: Britain, Germany, France, Japan, Canada, and Switzerland and Taiwan (the last two recently to reform managed health care). For those new to health care discussions, he explains the four different models.

1. Beveridge model – the government provides health care and finances it with taxes. Familiar to U.S. veterans.
2. Bismarck model – the private sector provides health care and the government regulates nonprofit insurance companies that cover everyone and that are financed by employers and employees. Familiar to working Americans.
3. National Health Insurance – the private sector provides health care and a government-run insurance program financed by citizens pays the bills. Familiar to Americans over 65.
4. Out-of-Pocket Model – if you have money, then you can see a doctor. If you don’t, you can’t.

A major takeaway point for me was the folly of having for-profit insurance companies. They exist to make money, so sick, expensive patients are bad for business, while denying claims and not covering preexisting conditions is good for business. Meanwhile, healthy, cheap twentysomethings don’t buy much insurance. As I understand it, if we want insurance companies to cover everyone, then everyone needs to pay for insurance (the individual mandate).

One theme was the difficulty of pleasing everyone. When the government regulates health care closely or is the single player, it has the power to negotiate very low prices for procedures and drugs. These low prices are good for patients and the federal budget, but they can squeeze drug companies and physicians something awful. Luckily, doctors in other countries don’t have pay nearly as much for their medical education, if they pay for it at all.

There’s a lot of interesting stuff I could get into, like Reid’s Ayurvedic treatment in India or France’s carte vitale. The book is accessible and entertaining, though, so I’ll just recommend going straight to the source.