Routine screening-such as mammograms for breast cancer-isn't saving lives, a new study has found. In fact, it may be doing more harm than good because it too often 'sees' diseases that aren't there, so triggering unnecessary treatment.
Two-thirds of routine screening tests do not save lives, despite the claims of governments and health officials, say researchers from Stanford University.
They looked at the results of 19 screening tests-including those for breast and prostate cancer, and cardiovascular disease-and found that just one-third saved lives. It's "uncommon" for just-in-case screening on healthy people to have any effect on mortality, said lead researcher John Ioannidis.
Expensive mass screening programmes should be reconsidered, and screening should be reviewed instead on a case-by-case basis, say the researchers. In any event, people should lower their expectations of what screening can provide.
And even when the screening produces a positive result-in other words, the disease it is looking for is detected-people should be suspicious. One study found that for every genuine case of breast cancer that a mammogram detects, it also "sees" 10 that aren't actually there.
(Source: International Journal of Epidemiology, 2015; doi: 10.1093/ije/dyu140)