Published 7/1/2009
Mary Ann Porucznik

Can you admit to being unsure?

Concept of “equipoise” challenges surgeons in clinical trials

Although most orthopaedic conditions can be treated in a variety of ways, practicing orthopaedic surgeons often believe they can recommend the “best” treatment for a patient, based on their understanding of the patient’s condition and history and their personal experiences.

When recruiting patients for a randomized clinical trial (RCT), however, orthopaedic surgeons must be able to admit that they don’t know what’s best for the patient—even if they think they do.

“Equipoise is a sense that two (or more) options are equally appropriate,” explained Bruce A. Levy, MD, during the AAOS/ORS Clinical Trials in Orthopaedics Research Symposium. “An RCT depends on two types of equipoise—community (clinical) equipoise and individual equipoise.”

Equipoise in clinical trials
According to Dr. Levy, community (clinical) equipoise exists when the community of clinical scientists deems both options appropriate. In developing RCTs, community equipoise is used to determine the entry and exclusion criteria, defining the population for which no solid evidence supports one treatment over another. It enables researchers to reach an ethical consensus for randomizing treatment.

Individual equipoise, on the other hand, is marked by clinical circumstances in which the investigator deems either option both clinically appropriate and ethically defensible. If the investigator’s individual equipoise matches the community equipoise, he or she will treat all eligible patients the same.

“Based on experience, however, a clinician may have a strong sense that one patient would benefit from surgery while another would not,” said Dr. Levy. “This creates a dilemma. Is it ethical for the clinician to recommend randomization if he or she believes that an eligible patient would—or would not—benefit from one of the treatment options?

“Does the clinician have to be truly uncertain about the outcome to justify enrolling a patient in a clinical trial?”

A single ethical framework doesn’t exist, noted Dr. Levy. “Some will argue that uncertainty is an ethical prerequisite for recommending randomization. Others will uphold the community equipoise as an ethical standard. In either case, the patient must be fully informed and must not feel coerced in making the decision of whether or not to participate.”

The impact on results
In a clinical trial, investigators may hold one of the following four positions:

  • I will enroll a patient only if I am truly uncertain about the appropriate treatment.
  • I will not enroll patients who, in my opinion, “need” surgery.
  • I will not enroll patients if the randomization results in “unnecessary” surgery.
  • I will enroll all patients who meet the eligibility criteria.

“If several of the surgeons who recruit for the trial do not enroll patients they think ‘need’ surgery,” said Dr. Levy, “the results will be skewed and will actually underestimate the value of surgery. Conversely, if most clinicians only refer patients who ‘need’ surgery, the results will overestimate the value of surgery. Either way, bias is created (Fig. 1).”

Dr. Levy offered the following take-home points to the audience. “RCTs are essential to establishing a base of clinical evidence, and randomization is the cornerstone of RCTs. Failing to preserve community equipoise contributes to a weak evidence base. It may be challenging for clinicians and patients—and especially challenging for surgeons—but the willingness to acknowledge uncertainty is key in developing RCTs that provide us with the evidence needed to make appropriate treatment decisions.”

Mary Ann Porucznik is managing editor of AAOS Now. She can be reached at porucznik@aaos.org