Don’t assume research findings from fair comparisons are not applicable to everyday life.
The effects of things people do for their health (health actions) in everyday life are likely to be similar to the effects found in fair comparisons by researchers, unless what is done in real-life is very different from the health actions in the research.
Explanation
Some people claim that evidence from fair comparisons of health actions in research is not relevant to real life. In fact, the effects of health actions in real life are unlikely to differ a lot from the findings of fair comparisons in research unless the differences between the health actions in everyday life and in the research are so clear that they are unlikely to work in the same way. Research findings from fair comparisons are only unlikely to be relevant if, for example, the doses or medicines, what people do, or the types of people in the research are very different from those in real life. Studies have compared the effects of health actions taken by people participating in fair comparisons by researchers to the effects of the same health actions taken by people not participating in that research. Those studies have found that on average, the benefits and harms of the health actions in real life (outside of the fair comparisons) were similar to the effects of the same health actions found in the fair comparisons. This challenges the idea that the results from fair comparisons in research are not relevant to real life.
However, the results of some comparisons may be less likely to be relevant than others. Some comparisons are designed to explore the effects of a health action in ideal circumstances (explanatory trials). Those comparisons may be less likely to be relevant in practice than comparisons that are designed to explore the effects of a treatment given in the circumstances of everyday life (pragmatic trials).
To avoid being misled by claims that fair comparisons in research are not relevant to real life, consider whether there really are any convincing reasons why a health action is unlikely to work the same way in everyday life as it did in the research.
Example
Because human biology is similar across people from different countries, races, and ethnicities, we expect health actions to have similar effects most of the time. So, it is not necessary to conduct fair comparisons of health actions in every country with large samples of people from every race and ethnicity. However, there are sometimes important differences. For example, it is well known that lowering high blood pressure reduces the chance of having heart disease (strokes and other cardiovascular diseases). There are many types of medicine used to lower blood pressure and there has been uncertainty about which of these is the best to use. There has also been uncertainty about whether these medicines work the same in Black people and in non-Black people. For this reason, North American researchers designed a fair comparison with 33,357 participants (35% Black) to compare different medicines for lowering blood pressure, and the research included a special analysis for Black participants. The effects of the different medicines were similar for Blacks and non-Blacks, except for the effect of one type of medicine called ACE inhibitors on strokes. Black participants (but not non-Black participants) given the ACE inhibitor were more likely to have a stroke than Black participants assigned to other medicines.
Remember: Unless there are good reasons to believe that health actions would work differently in real life, the results of fair comparisons by researchers are the best basis for deciding what to believe about the effects of health actions.
- Article: Does participation in a trial affect clinical outcome? Nature Reviews Clinical Oncology
- Blog: Clinical Trials: Reasons for wanting to take part in a clinical trial – personal benefit. Healthtalk.org