I blogged about this recently. Among other things I pointed out that an essential component of evidence based medicine (EBM) was involvement of the patient in the decision process by providing quality information. Although this important step is often ignored in discussions of EBM it was emphasized as a defining characteristic in the classic paper of David Sackett et.al. entitled “Evidence based medicine: what it is and what it isn’t.” The authors state that the process, among other things, involves “------the more thoughtful identification and compassionate use of individual patients' predicaments, rights, and preferences in making clinical decisions about their care.”
I discussed the concept of number needed to treat (NNT) as an understandable way to discuss the magnitude of treatment effects with patients. Then I ran across this recent study. It seems patients have difficulty with the concept. Decisions were influenced only marginally, if at all, by the NNT. In addition, 24% of patients who made a decision after being informed of the NNT changed their minds following additional explanation of the meaning of NNT. In almost all cases better understanding of the concept caused patients to reject the treatment in question. Worse, this paper from the August 1 issue of American Family Physician paints a dim picture of patients’ health literacy.
This is sobering. In my previous post I illustrated that the process was time consuming and challenging. These papers suggest that it’s even more challenging than we had thought.