Most primary care physicians misunderstand statistics about cancer screening, which could lead to increased testing with possibly harmful effects to patients, according to a new survey.
The survey published in the journal Annals of Internal Medicine presented more than 400 physicians with two scenarios of a hypothetical screening test. In one scenario the effect of the screening test was described as improved 5-year survival and the second as decreased cancer mortality.
Decreased mortality was ruled an appropriate measure of effectiveness, while the first scenario was deemed irrelevant because increased survival rates could be associated with simply early detection. Screening automatically increases survival rates because people live longer with cancer as opposed to someone who discovers the cancer relatively late.
More than three-in-four of the physicians surveyed stated that each of the statistics proved the screening saved lives. About half incorrectly said that finding more cases of cancer in screened as opposed to unscreened populations proves that screening saves lives, according to the article abstract.
“Most primary care physicians mistakenly interpreted improved survival and increased detection with screening as evidence that screening saves lives. Few correctly recognized that only reduced mortality in a randomized trial constitutes evidence of the benefit of screening,” the abstract states.
Advocacy groups such as the Susan G. Komen Foundation contribute to this misperception because survival rates sound more impressive, according to a Reuters article on the subject.
"This is really unfortunate because one of the things we always say is, 'Discuss it with your doctor,'" said Otis Brawley, MD, chief medical officer of the American Cancer Society told Reuters. "This is evidence that your doctor doesn't know."