I teach it course on human diseases for students in a public health program. One of the things that we talk about is asymptomatic disease. If a disease has no symptoms the only way that we can detect it is by screening. For screening to be beneficial it needs to be able to detect asymptomatic diseases accurately and there needs to be something which can be done that will help those in whom the asymptomatic disease is diagnosed. Many times, a screening test will only be accurate if the test is used to screen a selected population which is at risk. Sometimes there are asymptomatic diseases which we can detect accurately, but the people diagnosed do not benefit because there is not something we can do to make their life better than it would be if the asymptomatic disease had not been diagnosed. Since the purpose of screening is to help people, there is no reason to do it if the people being screened will not be helped. That idea is based on the principle of beneficence. Everything that we do in medicine should be done for the benefit of the person being treated.
Some people do not follow that moral principle. There have always been some who have used the practice of medicine to benefit themselves more than those they were treating. That is why the Hippocratic physicians had to put a statement about beneficence in their oath. One of the ways that the principle of beneficence can be violated is for some people to encourage other people to do screening that will not benefit those being screened but will benefit the one doing the screening. One of the examples I see most often is supposedly low cost ultrasound screening for such things as carotid stenosis. Those doing the screening can make a significant amount of money by screening everyone who will accept their pitch but the people being screened do not benefit. It is currently not recommended to screen for asymptomatic carotid stenosis because there is no evidence that intervention is beneficial for those who are diagnosed and some evidence that intervention may cause more harm than good.
As new technology is developed it is subject to being used in a way that violates the principle of beneficence. One of the new ways to do that is with genetic screening. A recent article in the health news section of Reuters.com describes the fraudulent promotion of genetic screening to older adults in the US. Again, this is screening being done to benefit screeners who have collected huge sums from Medicare while providing no benefit to those being screened.
These abuses do not mean that we should not do screening. It simply means that screening should be done the right way. We should choose which screening tests we use and which people we screen with those tests based on how the screening will benefit those who are being screened. We should not do it to benefit those who are doing the screening.