In a rebuttal to Stanley Shapiro and Kathleen Glass,1 David Sackett2 argues that a term such as “clinical equipoise” is useful only if it has a consistent meaning for everyone, describes something real and is in common currency. With regard to the latter, he states that because “uncertainty” yielded 292 860 hits on a MEDLINE PubMed search whereas “equipoise” yielded only 52, “uncertainty principle” would be a better term to use. However, “uncertainty” has many meanings and a search of “uncertainty principle” using PubMed (1966–present) yielded only 41 articles, of which only 8 were related to Sackett's use of the term. In comparison, a search of “clinical equipoise” yielded 29 articles, all of which were directly relevant to the topic. The term “uncertainty principle” therefore fails the tests of consistent meaning and of frequency of use.
Sackett also argues that bioethicists don't grasp the importance of the trust between individual patients and clinicians, and that the patient and clinician are often reasonably certain of which treatment is needed. This implies, I think inadvertently, that a patient should simply trust his or her clinician and never seek a second opinion. As a clinician and a researcher, I would suggest that in many areas of medicine different expert clinicians often have different opinions as to the most appropriate treatment. Indeed, in life- or limb-threatening conditions, or when a treatment has many side effects, patients should be encouraged to seek a second opinion. In essence, the concept of clinical equipoise as originally articulated by Benjamin Freedman3 simply suggests that where second opinions are likely to disagree, physicians should be willing to include their patients in a randomized controlled trial. Rather than prohibiting the clinician from informing the patient of his or her personal beliefs,2 clinical equipoise simply asks the clinician to be honest, letting the patient know that a different but equally competent clinician might decide on a different course. Of course, whether a randomized controlled trial should be done will also depend on the size of the patient population at risk and the cost, but this is an economic argument, not an ethical one. Understood in this light, I cannot agree with Sackett's conclusion that clinical equipoise is inconsistent with the “patient's autonomy and right to refuse to be randomized on the basis of their opinion, bias or certainty.”