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The Underrepresentation of You in Medical Research
Or, why a drug that helps me might kill you
You probably think taking a baby aspirin daily will reduce your risk of getting a blood clot. You’ve likely heard that a thousand times. It’s one of those pieces of medical common knowledge. But here’s the thing: it doesn’t work in about a third of people, and doctors don’t know why. It’s a phenomenon called aspirin resistance, and people who have it don’t get the anti-blood-clot benefits from the drug. But for people who do respond to aspirin, it works pretty well.
At the individual level, aspirin resistance is really important, obviously. But big randomized controlled trials suppress these important individual factors, leading to generic conclusions that don’t apply to a large swath of patients. Let’s simplify things a bit in attempt to discern how this works, then we’ll consider some other individual factors that don’t get captured by broad research conclusions.
For the sake of a thought experiment, assume that aspirin resistance is binary: aspirin either works for you or it doesn’t. Now, assume researchers take a random sample of 100 people, divide them randomly into two groups of 50, and give one group a placebo and the other aspirin. After a year, there were 20% fewer blood clots in the aspirin group than in the placebo group…
