The issue of informed consent

Many of us will have had a letter through the letterbox, "inviting" us to attend screening for cancer. Be it Cervical cancer, Breast cancer, Bowel cancer etc.

What's clear to me from these letters, and their accompanying information leaflets, is that we are not being given clear, impartial advice on which to make an informed decision.

They use headline statements like "5000 lives saved!", but don't tell you your actual risk of developing the disease, or the likelihood that you could be overdiagnosed, and overtreated, resulting in potential harm, both physically, and mentally.

So, what is necessary to make an informed decision? Firstly we should know what the risk of the disease would be, if we didn't choose to be screened. Secondly, we should know the risk of the disease, if we did choose to be screened. Thirdly, we should know the risk of being treated for a disease that we never actually had, or precancerous conditions that may not have gone on to cause disease.

Another point to consider, is all-cause mortality. For example, if 100,000 people are screened for disease A, and 20 cases of disease A are treated successfully, what are the chances that those 20 people would actually die from disease B, C, or D, in the same timeframe as they would have from disease A?

To illustrate this, if we screened women aged 80-90 for breast cancer, and picked up 3 cases, and treated them, how many of those 3 women would live beyond 90 anyway, without dying from another condition?

To make an informed decision, we need facts, evidence, and information to enable us to understand our individual risk. Most of the information provided to the public does not achieve this, and instead appears to encourage people to participate, giving a sense of risk in not doing so. We'll look into that later.

Screening relies on getting "people through the door". It relies on healthy people at little risk of disease submitting to screening, in order to find the few that do get the disease. The "needles in the haystack".