JBJS: Can Orthopedic Surgical Trials Be Blinded?
BY LAUREN UZDIENSKI, MAY 28, 2008
The double-blinded study is the gold standard of clinical research, but designing surgical trials to those standards can be difficult and often evokes such questionable options as sham surgery. However, one analysis of orthopedic surgical trials found that blinding may not be as much of a challenge as it seems. In their evaluation of 171 studies that they determined to be feasible for blinding, the authors identify a number of solutions that would reduce bias in results and are relatively simple to incorporate into study design.
The 171 studies, which covered a range of body regions and interventions, reported outcomes that were clinical (e.g., mortality or wound infection; 91% of trials), radiographic (83%), patient-reported (66%), and/or physiological results (e.g., range of motion; 56%). Less than 10% of these trials reported the use of blinded outcome assessors. According to an earlier study, 16% of all surgical studies are blinded, so even with the affirmation of the relative infrequency of surgical blinding, blinding in orthopedic surgeries appears particularly uncommon.
What is notable is that the authors found that the number of blinded assessors could have been much higher. They suggested that the use of such methods as independent assessors, concealed incisions and masked radiographs would have been feasible for 89% of clinical assessors, 89% of radiographic assessors, 96% of physiological assessors and 35% of patient-reported assessors. The authors excluded sham surgery as an option, given the ethical concerns.
One of the most resonant conclusions was the assertion that blinding shouldn't be considered all-or-nothing, but instead a continuum; "the more, the better," with some assessors aware of allocation and others blinded. As physicians, payers and other stakeholders demand more robust data, investigators implementing blinding could help to change industry norms and raise the bar for orthopedic surgical study design.
