Question: How should we interpret statements about the "increased risk" of disease?
he average adult is bombarded with "interpretations" of the latest health research by the media, bloggers and even celebrities. This research often includes numbers that can be misleading.
To interpret health research, we need to understand risk. The most frequently reported types of risk are relative and absolute risk. Relative risk, which is commonly reported by the media, involves comparing the occurrence of a specific condition in two groups such as smokers and non-smokers. Relative risk is how much greater (or sometimes less) the risk is for the groups.
Absolute risk, on the other hand, indicates the actual burden of a disease, or the number of individuals in a group that developed a condition per the total number of individuals researched.
Calculating risk usually requires advanced statistics. Study results are adjusted for confounders such as age, gender, traditional risk factors and genetic predispositions. Relative risk reported is usually the net effect of the researched factor, when other parameters have been considered. For example, according to the World Health Organisation, if someone eats 50 grams of processed meat per day, they have an 18 per cent increased risk of colorectal cancer compared to someone with the same adjusted parameters that does not eat processed meat.
Still, individual cases will vary, and not everyone eating 50 grams of processed meat daily will be diagnosed with colorectal cancer, while someone who avoids processed meats might.
Interpreting risk also depends on the study design. If a study reports relative risk after a decade of observation, the risk only refers to that time frame. For shorter or longer periods, risk may be very different. The way the risk factor is measured and reported also influences the results. For most foods there is no linear association with risk and this can only extend to specific amounts consumed.
The responsibility for translating research lies with researchers, reporters and industry. However, as a mindful consumer you can always question health headlines.
Even if a research finding sounds extraordinary and easy to implement, there are many lifestyle factors that will affect an individual's health status.
Response by: Dr Ekavi Georgousopoulou and Nathan D'Cunha, Faculty of Health, University of Canberra
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