NCPA - National Center for Policy Analysis


November 2, 2007

The proliferation of new health screens -- many not covered by insurance -- that try to detect disaster early in patients don't really work that well, says Forbes Magazine.

Many of the scans yield false-positive results, which lead to unnecessary (and risky) treatments.  Even recommended tests yield a scary number of false readings.  Take mammograms, an often promoted routine exam.  According to research compiled by the U.S. Agency for Healthcare Research and Quality:

  • The percentage of false-positive readings is between 7 percent and 8 percent for women aged 40 to 59 who took the test.
  • That figure drops to around 4 percent for women 60 to 79, mainly because the chances of getting breast cancer rise the older women get.
  • If every woman between 40 and 59 in the United States had a mammogram, a few million would be fretting unnecessarily over a wrong result.

Perhaps the most dubious of all the tests are total body scans, says Forbes.  According to recent research by G. Scott Gazelle, director of Massachusetts General Hospital's Institute for Technology Assessment:

  • Some 90.8 percent of patients who had a full-body scan got a least one positive finding that led to additional testing.
  • However, only 2 percent of those actually had a disease.
  • Worse, these tests cost between several hundred and several thousand dollars -- and most insurance companies won't cover them.

Not all tests are unreliable.  The United States Preventive Services Task Force says some commonly recommended tests including Pap smears, high blood-pressure tests, colorectal cancer screens and something called the Factor V Leiden test, which checks a person's predisposition to blood clots, deliver sufficient preventive value -- net of false readings and the risks association with doing further procedures based on them.

Source: Maureen Farrell, "The Scary Side Of Health Testing," Forbes Magazine, October 30, 2007.


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