Source: Brownstone Institute
by Alan Cassels
“What is the Healthy User Bias? It’s embarrassingly simple. In observational studies—where researchers merely watch what people do in the real world rather than running an experiment—the people who voluntarily take preventive drugs or pop daily supplements are fundamentally different from those who don’t. No surprise there, right? On average, ‘healthy users’ are wealthier, better educated, and more health-obsessed. They are seriously more obedient when it comes to vaccines (including the Covid vaccine). These sorts of people want to do the best they can within their powers, which includes things that involve some friction: they eat organic kale, jog at dawn, wear seatbelts, don’t smoke, and visit their doctors regularly. They love tests of all kinds. A 2006 meta-analysis quantified the healthy user effect (which they called the healthy adherer effect) across 21 studies. What they found is mind-blowing in its implications.” (09/29/26)
https://brownstone.org/articles/why-observational-studies-lie-to-you/