Equipoise

Equipoise is a state of balance or equality between opposing factors. The term is used in philosophy and ethics to describe a situation in which arguments for and against a proposition are equally persuasive at a given moment. It derives from Latin aequus meaning equal and poise meaning balance.

In medical ethics, clinical equipoise refers to genuine uncertainty within the expert medical community about which of two or more treatments is most beneficial. This uncertainty justifies the conduct of randomized controlled trials because no treatment is known to be superior for the population being studied. Individual equipoise, by contrast, describes a clinician’s personal lack of preference between options for a specific patient.

Applications and implications: The existence of clinical equipoise supports ethical trial enrollment, informed consent, and trial design. If credible evidence emerges that one intervention is superior, ongoing randomization is questioned or halted until new data clarify the best approach.

History: The concept of clinical equipoise was articulated in the late 1980s by medical ethicist Benjamin Freedman, and it has since become a standard criterion in guidelines for human research.

Limitations and debates: Some scholars argue that establishing equipoise is challenging in evolving fields, that it may be difficult to measure, or that the standard should be revised to accommodate patient preferences and adaptive trial designs.