Patients asked to estimate how many lives would be saved through cancer screening or how many hip fractures can be prevented with bone-building medication mostly overestimate the benefits of these preventive measures, according to a New Zealand study.
Several hundred patients were asked about the benefits of various cancer screenings and were surprised by how small the benefits actually were, according to findings that appeared in the Annals of Family Medicine.
Doctors, nurses and other medical professionals who communicate health information often don't detail how much a given test or drug can help, but only say that people ought to have it, said Annette O'Connor at the University of Ottawa, who wasn't a part of the study.
I think it's led to more people taking part in screening or availing themselves of preventive medication than would have been the case if they were presented the information in more meaningful terms, said lead author Ben Hudson, a professor at the University of Otago in Christchurch, New Zealand.
I would also be concerned that it's led to people having over-heightened expectations of what these things can achieve, and that may lead to disappointment when the inevitable breast cancer happens despite screening.
To get a broader sense of patients' expectations, Hudson and his colleagues asked 354 people about the benefits of breast cancer screening with mammograms, bowel cancer screening with stool testing, taking antihypertension medication and taking bone-strengthening medication.
Specifically, participants were asked to imagine scenarios in which 5,000 people between the ages of 50 and 70 undergo one of these preventive interventions for 10 years, then asked how many events' they thought would be avoided as a result.
For three of the four interventions, the event to be avoided was death. In the case of the bone drugs, it was hip fracture.
For breast cancer screening, only seven percent of the participants answered in the correct range of one to five lives being saved with screening, whereas 80 percent overestimated how many lives would be saved. Fully a third thought that 1,000 deaths would be averted.
The numbers were similar for bowel