Ideal conditions for an N-of-1 trial

You can’t use an N-of-1 trial for just any research study. N-of-1 trials are most helpful under these circumstances:

  1. There’s some uncertainty about which treatment works best for this particular individual (otherwise, why bother?).
  2. There’s evidence that different people have different experiences with these treatments (which is why it’s worth testing for each person).
  3. Participants have a stable, chronic condition that can improve, but not go away (because if the first treatment fixes the issue, you can’t really test the effect of the other treatments).
  4. Each potential treatment can take effect quickly and fade quickly (it would take a long time to test your options if the first medication took four weeks to kick in and another four weeks to leave your system)
  5. Proof that this treatment is working (or not working) is measurable and easy to collect.