New Heart Risk “Calculator” : Health care decisions from an Excel sheet?

I was just reading an article on the NYT which described a new method that doctors can use to decide whether to put patients on statins or not.

Statins work to prevent cardiac events by reducing cholesterol levels. While widely used, they are controversial as a means to prevent heart attacks in people without cardio-vascular disease.

As a public health guy, I’m interested in health diagnostics. So when I noticed that this hi-tech “calculator” was available for download from the NYT article, I immediately opened it up. I expected some sweet Java-based interface, with boxes to check a number of things like age, weight, ethnicity, dietary and exercise habits and family health history.

To my dismay, I found that it’s an Excel spreadsheet with space to enter ten items:

CVDCalc

As you can see, I filled in my own information (as best I could, based on recall).

I was happy to see that my lifetime risk of CVD is a mere 5% and, as I resist taking medications of any kind, even more happy to see that a doctor would likely not prescribe me statins.

However, I’m not sure what this really tell me. Does this say that I don’t have to exercise anymore? Can I eat tons of fried crap and finally ignore my family’s host of health problems now?

Mostly, I’m struck by how arbitrary this is. Smoking, high blood pressure, advanced age, being male and being African American are all known predictors of CVD. The absence of potentially modifying factors such as diet and exercise just make the picture even more arbitrary. I may be old, black and male, but I may have made lifestyle changes to counter those factors, thus reducing my risk for disease.

More frightening to me is how ad hoc medical care is. Doctors are praised for “shooting from the hip,” or making diagnoses based on gut feeling. In most cases, this is satisfactory. Sometimes health problems resolve themselves, or are too serious to effectively treat in the first place. Other times, this can lead to over prescription of medications or uninformed (praise god for the internet!) “patient directed medical care.” Though this calculator attempts to counter that behavior, I fear that its cheap simplicity makes a mockery of quantitative diagnoses of health risks, undermining the project’s goals.

The truth is, of course, that we really don’t know enough about complex diseases such as CVD. Though medicine is able to spot obvious candidates for serious disease (particularly after one develops it), the truth is that no one can say for certain whether, absent the obvious, one person is more likely to become ill than another. This calculator doesn’t change that.

It was a great epiphany for me when I realized that, though I am at low risk for CVD, given my expected long life expectancy, I am more likely to die due to, you guessed it, heart disease.

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About Pete Larson

Assistant Professor of Epidemiology at the Nagasaki University Institute for Tropical Medicine

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