It is not surprising that David Sackett1,2 disagrees with Stanley Shapiro and Kathleen Glass;3 they are talking about different things.
A clinical trial involves decisions at 3 distinct levels: that of society, the individual physician and the patient.
The decision on whether a proposed trial should be carried out is formally taken by a research ethics board (REB), which, in effect, must decide whether asking patients to consent to participate is consistent with the standards of society as a whole. The concept of clinical equipoise is an essential part of the REB's decision; the REB must be confident that expert clinical opinion regards the trial as valid.
Individual clinicians must decide whether they should enter patients into the trial. The concept of uncertainty addresses this decision.
The consent of the patient is requested by the uncertain physician on a case-by-case basis if he or she believes that the uncertainty for a population of patients applies to the specific case.
The term “clinical equipoise,” though perhaps ungainly, effectively captures the valuable concept of collective expert uncertainty and differentiates it from individual uncertainty, which may be insufficient justification for a trial.
Signature
Francis Rolleston
Ottawa, Ont.
References
- 1.Sackett DL. Why randomized controlled trials fail but needn't: 1. Failure to gain “coal-face” commitment and to use the uncertainty principle. CMAJ 2000;162(9):1311-4. [PMC free article] [PubMed]
- 2.Sackett DL. Equipoise, a term whose time (if it ever came) has surely gone [editorial]. CMAJ 2000;163(7):835-6. [PMC free article] [PubMed]
- 3.Shapiro SH, Glass KC. Why Sackett's analysis of randomized controlled trials fails, but needn't [editorial]. CMAJ 2000;163(7):834-5. [PMC free article] [PubMed]