The British Medical Journal published a thought-provoking systematic review of breast cancer screening programs which revealed that up to 50% of cases identified represent an “overdiagnosis” which was defined as the “detection of cancers that will not cause death or symptoms”. The authors extracted data from previously conducted trials and estimated the incidence of breast cancer before and after the introduction of screening programs.
Let me just repeat this finding – over 50% of cases represented an overdiagnosis. This means over 50% of the time, money, time and emotions were spent on identifying a cancer that would not have caused any trouble.
In the context of global health, where we try to make the most of a little, and as we strive to expand and develop health systems in developing counties, this kind of data should caution us about starting large-scale prevention programs. While we ideally want to level the playing field and offer the same quality of care, I think we should be very cautious about spending on prevention programs. In many developing countries we have a long way to go in providing what we consider ‘standard of care’ for even the most common conditions. I think it’s very reasonable to have a high bar for money spent on prevention, especially interventions that are costly and involved such as mammograms.
Before we create populations of women who expect to get screened, let’s choose our interventions judiciously so that money spent on improving health care is spent where there is the best ‘value’ for money. This concept of ‘rationing’ health care (discussed in a recent New York Times article) is somewhat taboo to discuss in the US- but where health care resources are scant (such as in Africa) rationing is expected. We need good ‘bang for the buck’ where the bucks are scarce.
Essentially, this comes back to my comment that interventions in global health should be evidence-based…and where the evidence, is scant, I am suggesting we err on the side of being conservative on screening – the opportunity cost for that money is huge.