Related Resources • EBCT - Godsend or Scam? • Risk factors

By DrRich

Dateline: 05/12/03

Electron-beam computerized tomography (EBCT), also known as ultrafast CT, is a relatively new technique of screening for coronary artery disease in asymptomatic people.  Because most insurance companies and Medicare have declined to cover this diagnostic test, EBCT is being widely marketed to the general public.

The mass marketing approach to EBCT has generated significant controversy. Critics argue that unsuspecting individuals are being lured into an unproven test that costs them money out of their own pocket, and that is not proven to be any more accurate than standard risk-factor assessment.  Further, EBCT too often leads to unnecessary and potentially risky cardiac catheterizations, thus wasting the health care system's money.  Proponents counter that a normal EBCT test can give healthy people peace of mind, while an abnormal test can reveal a dangerous health problem while there is still time to treat it.  And at the very least, an abnormal EBCT can motivate patients whose lifestyles place them at increased risk to change their behavior and reduce that risk.  Indeed, the "motivation to change behavior" argument is central to many proponents of EBCT.  (Click here for a review of EBCT scans, how they work, and whether they are accurate at predicting coronary artery disease.)

This week, an article published in the Journal of the American Medical Association describes a study whose aim was to see whether EBCT will motivate individuals to reduce their cardiac risk factors. The conclusion: it sure doesn't look like it.

The study enrolled 450 apparently healthy members of the US Army between 39 and 45 years of age. Subjects had EBCT scans, and then were randomized to groups that were shown the results of their EBCT scans, and those who were not.  The two groups were further divided into those who received intensive risk-factor management coaching (detailed explanations of risk factors by specialized nurses, follow-up phone calls and visits) and those who received "usual" risk factor management from their primary care doctors.

The findings of this study include:

•     there was no difference in risk factor modification among those who saw their EBCT and those who did not
•     those who received intensive coaching had an improvement in risk factors - whether they saw their EBCT results or not
•     those who recieved "usual" risk factor management did not change their behaviors - whether they saw their EBCT results or not
•     among those who had abnormal EBCTs, seeing the results of their scans did not yield a significant improvement in risk factors

Thus, this new study calls into question the notion that having an EBCT will motivate people to improve their behavior with regard to cardiac risk factors, and shoots a large hole through one of the major arguments promulgated by proponents of EBCT.  (It also reconfirms that doctors are doing a lousy job coaching their patients in risk factor modification.)

What do these results mean to you?

A study that shows the average behavior of a large group of people, in response to some stimulus, can help society decide whether to pay for that "stimulus."   But such a study does not necessarily help an individual predict how he or she will behave in response to that same stimulus.  And besides, when the individual is paying for the stimulus him/herself, what right does society have to judge whether he/she is likely to be sufficiently motivated, by this personal expenditure, to live a healthier life?

If you are considering an EBCT scan in order to "goose" yourself into living a healthier lifestyle, take this new study into account.  If you already know you have one or more risk factors for coronary artery disease (obesity, lack of exercise, hypertension, elevated cholesterol and triglycerides, smoking) and haven't already changed your risky behavior, ask yourself: will seeing a glob of calcium on your coronary arteries be the just impetus you need? 

In any case, DrRich suspects that most patients who decide to buy themselves an EBCT scan are not doing it to give themselves an incentive to engage in behavior modification.  They are doing it to screen for the presence of coronary artery disease.  Whether EBCT is a good way to do this or not (a question we have considered elsewhere), the results of this trial are not likely to impact significantly on those individual spending decisions.