BACKGROUND: Blinding personnel in randomized controlled trials is an important strategy to minimize bias and increase the validity of the results. Trials of surgical interventions present blinding challenges not seen in drug trials. How often orthopaedic trauma investigators undertake blinding, and the frequency with which they could potentially utilize blinding, remains uncertain.
METHODS: We conducted a systematic review of all randomized controlled trials of orthopaedic trauma published from 1995 to 2004. Two reviewers assessed each trial for eligibility and extracted data regarding its characteristics, outcomes, reporting of blinding, and feasibility of blinding.
RESULTS: We included 171 unique randomized controlled trials spanning a variety of body regions and interventions. The most commonly reported outcomes were clinical (e.g., mortality or wound infection; 91% of trials), radiographic (83%), patient-reported (66%), and physiological results (e.g., range of motion; 56%). Less than 10% of the trials in each category reported the use of blinded outcome assessors. This contrasted with blinding that investigators could have accomplished: blinding was feasible with use of simple methods such as independent assessors, concealed incisions, and masked radiographs for 89% of clinical assessors, 89% of radiographic assessors, 96% of physiological assessors, and 35% of patient-reported assessors.
CONCLUSIONS: Trials in orthopaedic trauma typically measure many outcomes requiring judgment, but the individuals assessing those outcomes are seldom blinded. Investigators have the opportunity to enhance the validity of future clinical trials by incorporating simple blinding techniques.
Karanicolas, Paul J. and Mohit Bhandari, Behzad Taromi, Elie A. Akl, Dirk Bassler, Pablo Alonso-Coello, David Rigau, Dianne Bryant, Shona E. Smith, Stephen D.Walter, Gordon H. Guyatt
Disease Category: Orthopaedics & trauma
Disease Name: Fractures
Age Range: Unknown
Sex: Either
Nature of Intervention: Not specified
- None
- Systematic review of outcomes measured in trials
- Systematic review
We searched four electronic databases (Medline, EMBASE, CINAHL, and CENTRAL) using the following terms: fractures, orthopaedic procedures, fractures/surgery, and fracture fixation. We limited our search to human, English-language, randomized controlled trials published between the years of 1995 and 2004. Two reviewers independently assessed the titles and abstracts of all citations to determine whether they met the following eligibility criteria: the study was a randomized controlled trial; the participants were living humans with a fracture of any bone, excluding bones of the head, due to injury; at least one of the interventions occurred in an operating room and involved an incision; and the study was a full-text, English-language manuscript published in a biomedical journal.
Two reviewers independently applied the eligibility criteria to the full text of all potentially eligible studies. They met and resolved disagreements by discussion and consensus. We combined manuscripts that reported on the same primary trial (such as those with longer follow-up or subgroup analysis).
Two reviewers independently extracted data in duplicate regarding participants, interventions, outcomes, and methodology from each eligible trial using a standardized Internet-based system. We performed a pilot test of the clarity of our data forms by having all reviewers assess four trials in orthopaedic trauma from outside the time frame used in this study. A third individual reviewed all disagreements and made the final decision.
We classified outcomes as follows: (1) clinical outcomes rated by a clinician or by chart abstraction (e.g., mortality, infection, length of stay, cost, repeat operation, operative and/or fluoroscopy time, complications, or transfusions); (2) physiological outcomes rated by a tester (e.g., range of motion, strength, gait and/or weight-bearing, stability, or functional scores); (3) patient-reported outcomes (e.g., pain, analgesic use, function, or quality-of-life score); (4) radiographic outcomes (e.g., quality of reduction and/or alignment, implant placement, fracture-healing and/or union, or implant failure); and (5) combined outcomes incorporating two or more categories of outcome assessors (e.g., fracture-healing with use of a combined clinical and radiographic assessment).