I am not questioning the idea that medical decisions ought to be based on evidence. All doctors should do this. But from a dispositionalist perspective, the evidence on which medical decisions should be based must have a different priority than what is currently the case in evidence-based medicine. This is how:
- Evidence about causal mechanisms – that is, how the intervention does its causal work – must be given epistemic priority over how often it works in a population.
- Qualitative methods are better suited than quantitative methods for understanding such mechanisms, since they allow us to study complex interactions.
- Case-studies are important for picking up on unexpected effects, and to develop our causal knowledge about a treatment, especially if these are too rare to show up in population trials.
- If we understand how the treatment works, we might also be able to assess risk better in the individual case, and for long-term effects.
- Individual propensities can be found by considering causal mechanisms and intrinsic properties, not derived from statistical frequencies.
- Treatment ought to be tailored to the individual rather than advised based on statistical evidence alone.
- The same intervention in different contexts should not be expected to give the same effect.
- Knowledge about the individual patient is essential before making decisions about treatment.
- That a condition is medically unexplained does not mean that no cause is found. Rather, it means that a cause cannot be backed up by statistical evidence.
