Communicating to lay people about the risks and other downsides of diagnostic testing has been challenging. Lay people have tended to consider diagnostic tests to be inherently valuable and safe, and worrying about their harms can be counterintuitive for them. Yet many wish to be better informed about the potential risks of diagnostic testing. Some are concerned about overtesting and overdiagnosis.

Lay peoples’ interpretations of messages about testing risks are likely informed by their broader beliefs and experiences. It is possible that among some, acceptance of information about testing risks may be also predicted by potentially problematic health beliefs, such as rejection of mainstream medicine. But research is lacking. It is needed, to inform the development of more targeted messaging about testing risks and benefits. It may also help communicators avoid stoking undue distrust when communicating important information about overtesting to the public.

Our study examined how Australians’ attitudes to asking about risks and other downsides when offered diagnostic testing were predicted by their i) other beliefs about diagnostic testing, ii) broader health beliefs, and iii) demographics.

We surveyed 774 adults from across Australia between January - April 2022. We examined a range of their beliefs related to diagnostic testing, and used validated measures to assess their health literacy (HLQ), healthcare distrust (HCSDS-R), beliefs in alternative and holistic medicine (HCAMQ) and self-rated healthiness. We also measured a range of demographic variables.

Descriptive statistics were used to summarise survey responses. Chi2 or Fisher’s exact test were used to assess the relationships between the outcome variable: attitudes to asking about risks and downsides when offered diagnostic testing, and other beliefs and demographics. Regression analysis examined how broader beliefs and demographics predicted responses on the outcome variable. The level of significance was set at p<0.005.

We achieved a diverse non-representative sample: 57% of participants were aged over 55; 49% were male, 47% female and 4% identified with another gender; 59% had children. Most were born in Australia (72%) and lived in metropolitan areas (64%). University-educated participants were overrepresented (66%).

Among participants, 86% believed that it was important to ask about risks and other downsides when offered diagnostic testing. Responses about other testing beliefs indicated a range of potential barriers as well as promoters to accepting messages about overtesting. Predictive analysis is ongoing, but the findings will be presented at the conference.

This research will help us understand which groups are most willing to ask about risks and downsides when faced with decisions about diagnostic tests, and the factors related to this willingness. The research will help us tailor communications about overtesting, and understand whether acceptance of overtesting messages is related to distrust and rejection of mainstream medicine, adherence to complementary medicine or health literacy levels.