Diving into the reliability problem with 'self-reported data'

“Self-reported data” is often a caveat for studies, and a new study breaks down why. Looking at data from around 100,000 older adults across 17 European countries, researchers found that people tend to exaggerate or underestimate health problems. People were asked to self-report problems with mobility, for example, and some 19% of people reported trouble getting up from a chair after sitting for a long time. But when scientists assessed people directly, they found that figure was closer to 17%. The study also found that the discrepancy between actual and self-reported data increased with age: More than 85% of those in the 50-54 age group correctly estimated their mobility, whereas only 66% in the 90-94 group did the same. Self-reported data are often the only ones used in research, the authors write, and so lawmakers writing policies based on such research should consider that it may not always be reliable.