Screening healthy people for possible disease is often seen as a way of preventing serious health problems. But how much do you know about the benefits–and the risks–of screening? Whether it is regular mammography for healthy women or PSA tests in men with no symptoms of prostate trouble, screening can detect abnormalities that would never cause harm. Investigating them further, however, does have a potential for harm.
This issue can be emotionally charged, as the response to the recent article on mammography in the BMJ demonstrated. Although the scientists found no survival benefit from screening mammography after a follow-up of 25 years, many women insisted that a screening mammogram had saved their lives.
For a better understanding of the potential for overdiagnosis and how it could lead to overtreatment, we explore the concept of the number needed to treat: the NNT. How many people need to take a cholesterol-lowering drug for one life to be saved?
Guests: Alan Cassels is co-author, with Ray Moynihan, of Selling Sickness: How the World’s Biggest Pharmaceutical Companies Are Turning Us All into Patients and co-author, with Gil Welch, of Seeking Sickness: Medical Screening and the Misguided Hunt for Disease. The photo is of Mr. Cassels.
David Newman, MD, is director of clinical research and professor of Emergency Medicine at the Icahn School of Medicine at Mt. Sinai Hospital in New York City. His website is thennt.com
The podcast of this program will be available the Monday after the broadcast date. The show can be streamed online from this site and podcasts can be downloaded for free for four weeks after the date of broadcast. After that time has passed, digital downloads are available for $2.99. CDs may be purchased at any time after broadcast for $9.99.