Screening tests have become a major component of modern healthcare, but a new study finds they may not save as many lives as generally thought.
Common screening tests include colonoscopy, mammograms, pap tests, PSA tests, chest X-rays, and many others.
Although such tests used to be considered harmless at worst, some screenings have come under fire for needlessly exposing patients to cancer-causing radiation or for leading to unnecessary or overtreatment.
Stanford University of Medicine researchers evaluated the results of 143 studies that examined screening tests for abdominal aortic aneurysm, breast cancer, cervical cancer, colorectal cancer, hepatocellular cancer, lung cancer, oral cancer, ovarian cancer, prostate cancer, Type 2 diabetes, and heart disease.
Scientists found that tests for these diseases on people showing no symptoms rarely save lives.
"Our comprehensive overview shows that documented reductions in disease-specific mortality in randomized trials of screening for major diseases are uncommon,” said senior author John Ioannidis, a Stanford professor.
Such tests should be performed on a case-by-case basis and the expectations of patients should be tempered, the researchers added. The study was published in the International Journal of Epidemiology.
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