Patients are deceived over benefits and risks of screening, MPs hear

Patients are prone to “deception” about the real risks and benefits of national screening in the United Kingdom, MPs have been told.

The full pros and cons of screening patients were too often poorly explained, skated over, or presented in a confusing manner, expert witnesses said during an evidence session of the House of Commons science and technology committee’s inquiry into national health screening.

MPs asked whether patients who agreed to participate in screening programmes fully understood the risks and benefits.

One witness was the former breast cancer surgeon Michael Baum, professor emeritus of surgery and visiting professor of medical humanities at University College London, representing Advocates for Honesty and Transparency in Breast Screening. He said, “I share your concern about how risks and benefits are described.

“A fundamental problem in screening for cancer is that the proponents for screening use relative risks, which not only do lay people not understand, [but] most of my professional colleagues don’t understand.”

He gave the example of a clinician telling a patient that screening for breast cancer has a relative risk reduction of 15% in breast cancer mortality—which, when translated into absolute terms, means that professionals have to screen 1000 to 2000 women for 10 years to prevent one death from breast cancer.

“It is unethical to deny innocent, lay women that knowledge when they come to make a decision as to whether or not to go for screening,” said Baum, adding that there were better ways of explaining risks and benefits in an understandable way, such as by using “info-graphics.”

“The group I represent are mostly lay people who are not trained in statistics or medicine but are wise enough to see the deception that is going on,” he told MPs. “There is a group of public health doctors and Department of Health officials who sincerely believe that the benefit outweighs the harm. The danger is that they select advisers who constantly reinforce that message.

“We would not advocate dismantling the screening programme, but improving it. We are stuck in a time warp, and what we are doing now is what was set up in 1988. Stuff has moved on since then.”

A fellow witness was Robert Meadowcroft, chief executive of the Muscular Dystrophy Campaign, who said that he would look to professional bodies such as the British Myology Society—experts on muscle disease—for help in developing public information about screening programmes.

“There are lead professionals who I am sure would be delighted to advise on information for parents,” he said. “We would want to make sure the language is accessible. Information on screening has to be road tested with different groups of parents and families.”

Andrew Miller, the committee chairman and Labour MP for Ellesmere Port and Neston, said, “My own experience is that on the whole, doctors aren’t actually very good at explaining risk to members of the public.”

Margaret McCartney, a GP from Glasgow, also giving evidence, said, “I would concur with that. When you look at the work that statisticians have done about how well the public understand basic statistics, it’s pretty poor.

“So you are starting from a really difficult position where I’ve got lots of information that I want to try to give to my patients, but that information is quite difficult. It takes a lot of time and energy when there’s lots of competing priorities in the consulting room. I think it is very difficult and we aren’t very good at it.”