HI readers respond: The downside of screening

The recent article “More bang for the buck? Lung CT screening brings opportunity to detect other diseases,” in HealthImaging about extra benefits of a lung cancer screening program by Lisa Fratt prompted me to comment from the real world about the practical frustrations of screening medical tests that this situation represents. I say this as someone very familiar with the debate about the pros and cons of coronary artery calcium screening. It is a great test in some people and clearly can enhance our understanding of who is a higher risk of clinical trouble and who is not. Plus the lungs are imaged: logically this could be a screening “win win.”

The trouble is that gray zone where findings are not normal and treating physicians are asked to decide if a modest calcium score or a small lung nodule is actually the going to be life changing for the patient or is it something clinically incidental that can be ignored.

For good screening results, we need high sensitivity and calcium scoring certainly qualifies. But then a positive score needs a specific follow-up test. And what would that be? A heart catheterization? A perfusion exercise test? Since we are talking about screening, this is testing asymptomatic people (who are admittedly at a higher “risk”) where the argument for an intervention of any sort is difficult to advocate for.

This is why I think screening programs and opportunities, however logical, spell trouble: we treating physicians don’t really know what to do with an abnormal result.  And it creeps into our compassionate psyche: we don’t want to miss anything. We proudly remember a shrewd diagnosis from a tiny clue: we can’t help being more interested in sensitivity than specificity. Put a positive score in front of a well-meaning MD and a flood of new consultations and tests predictably ensues: funny chest pains become possible angina, a borderline ECG becomes cannot exclude ischemia, palpitations become possible V tach. It is sad but true. For all the good that early disease discovery does in heart disease management, I actually don’t think that it is worth it because of the escalated worry and follow-up testing that ensues.

And, I don’t think this will change until our hearts become a little colder with the new economics of healthcare and rationing of our resources. Radiology benefit management companies (RBMs) will increasingly influence what tests will be paid for and what tests will not. Like them or not, RBMS are the enforcers of the conclusions of medical society’s appropriate use criteria and clinical trial implications. We resent their push-back against our instincts for a diagnosis, but that push-back is here to stay. When we are actually forced to do more with less, it may turn out that well-intended screening wasn't actually that consequential anyway. It seems a paradoxical and depressing conclusion, and we can’t prove this with a new clinical trial either; our practice habits will just have to evolve.

Carter Newton, MD, FACC