General health checks don’t work

We check our cars regularly, so why shouldn’t we also check our bodies so that we can find and treat abnormalities before they cause too much harm? It seems so easy, but the human body is not a car, and, in contrast to a car, it has self healing properties. Actually, the first thing we know about screening is that it will cause harm in some people. This is why we need randomised trials to find out whether screening does more good than harm before we decide whether to introduce it.

Doctors realised this early on and embarked on 16 randomised trials of general health checks between 1963 and 1999. A Cochrane review from 2012 that included 11 940 deaths did not find an effect of general health checks on total mortality (risk ratio 0.99, 95% confidence interval 0.95 to 1.03) or on mortality due to cardiovascular disease (1.03, 0.91 to 1.17) or cancer (1.01, 0.92 to 1.12).1 2

These trials were carried out in Europe and in the United States. The most recent one, the Danish Inter99 trial, which started in 1999, reports its results …