MORE transparent information about screening may mean consumers are more likely to choose not to screen, but doctors have no reason to be concerned, according to a group of Australian researchers.

They maintain that greater transparency is needed in information about cancer screening to better inform people about the benefits and the harms of screening.

Associate Professor Dr Lyndal Trevena, head of the University of Sydney Medical School’s Office for Global Health and a general practitioner, and clinical researchers Dr Sian Smith and Dr Kirsten McCaffery told MJA InSight that while there was good evidence in support of an Australian bowel-screening program, they believed that information to support an informed choice in screening should be available for people who want it.

They said practitioners constantly had to balance patient autonomy with public health recommendations.

“However, without good, balanced information, practitioners are left even less confident that such decisions by patients are properly informed,” they said.

They were commenting after publication of their study in the BMJ to determine whether a decision aid, designed for adults with low education and literacy, supported informed choice and involvement in decisions about screening for bowel cancer.(1)

In a NSW trial, 572 adults aged 55–64 years with low education and literacy were randomised to receive either a decision aid booklet and DVD, which presented risk information on faecal occult blood test (FOBT) screening compared with no testing, or a standard information booklet developed as part of the Australian national bowel cancer screening program (control group).

All participants received a FOBT kit for self-sampling.

The decision aid improved understanding about the number of people who died naturally from bowel cancer without screening (baseline risk) and the number of lives saved by screening (absolute risk reduction), the authors said.

The decision aid increased the proportion of participants who made an informed choice, from 12% in the control group to 34% in the decision-aid group.

Although the decision aid did not make people more worried about developing bowel cancer, it did make them feel less positive about screening, and reduced uptake of the screening test by 16% (75% in the control group versus 59% in the decision-aid groups).

“It seems that this may have resulted from increasing their knowledge about the low personal benefit of screening,” the study authors said.

They suggested the decision aid could be made available through GPs or national screening providers as a web or paper-based tool.

An accompanying BMJ editorial said that to increase informed uptake of FOBT, changes to the information provided might be needed so risks and benefits of screening are described in a way that encourages adherence to recommendations.(2)

The editorial also suggested changes to the screening pack, such as the addition of disposable gloves, so barriers to performing a screening test were reduced.

In a separate study  from Denmark, it was found that the combined effect of adherence to recommendations for five lifestyle factors — smoking, alcohol intake, physical activity, waist circumference and diet — had a protective effect on the risk of colorectal cancer.(3)

In the study of 55 487 middle-aged Danish men and women without cancer at baseline, 678 participants developed colorectal cancer during a median follow-up of almost 10 years.

The study found that if all participants managed to improve their lifestyle by following merely one additional recommendation, 13% of cases of colorectal cancer might have been prevented.

If all participants had followed the five recommendations, 23% of the colorectal cancer cases might have been prevented.

The BMJ editorial said for mortality from bowel cancer to be reduced, adults needed to adhere to lifestyle recommendations or have the screening test, or both.(2)

1. BMJ 2010; 341: c5370
2. BMJ 2010; 341: c5407
3. BMJ 2010; 341: c5504

Image courtesy of Bowel Cancer Australia


Posted 1 November 2010

2 thoughts on “Is a little more knowledge a dangerous thing?

  1. Belinda says:

    I think the issue with this, Rick, is that a colonoscopy is not a benign procedure – it may involve a general anaesthetic.

  2. Rick says:

    FOBT, in my view, is a waste of time on an individual basis (as a population screening tool – that’s another matter). One can’t recommend it to patients and give them any assurance that they’re OK if it’s negative.
    In fact, most doctors I know are opting to have colonoscopies at around age 50. They clearly see this as the best screening tool.

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