This post is part of a series where I elaborate on questions I was asked after my keynote in the 13th International Shared Decision Making (ISDM) Conference, hosted at Dartmouth College, USA, July 7, 2026 to July 10, 2026. From the conference website: “With the 2026 theme, ‘A Wider Lens,’ this year’s conference will bring together clinicians, researchers, patients, and policy leaders to expand our understanding of shared decision-making across specialties, care settings, and systems.” You can find links to my recorded keynote and to the other posts in the series at the end of this post.

The question I was asked (paraphrased by me):

“How can we trust patients’ knowledge when there are anti-vaxxers and science deniers?”

It is an important distinction to draw. In my presentation I am NOT arguing “trust whatever a patient believes.” I’m describing a specific, bounded kind of knowledge: systematic observation about your own body, tested through a question-observe-reason-explain cycle, validated by what actually happens when you act on it. Vaccine hesitancy is usually about generalizing from anecdote to population-level causal claims — exactly the kind of claim personal science isn’t suited to make. Phronesis is expertise about your own case, not a substitute for epidemiological evidence. What I want is better ways of recognizing and validating the former, not a blanket “trust patients or don’t” switch.

Here are links to the other posts in this series:

• My recorded keynote for ISDM2026
• “How can we trust patients’ knowledge when there are anti-vaxxers and science deniers?”
• “What’s your opinion on healthcare delivered patient education?”
• “Who takes responsibility if the new way of taking pills harms other patients?”
• “Is epistemic injustice equally distributed, or stratified?”
• “How could we elicit Chronic Knowledge during a consultation? What question would you want to be asked?”
• “Is shared decision making ready to see the blue dots?”