Superiority Claims for Spinal Devices: A Systematic Review of Randomized Controlled Trials

Area of Science:

• Biomedical Engineering
• Clinical Trials
• Medical Device Research

Background:

• Superiority claims for medical devices are frequently based on noninferiority trials, posing interpretation challenges.
• Understanding the prevalence and validity of these claims is essential for evidence-based healthcare decisions.

Purpose of the Study:

• To determine the proportion of noninferiority and superiority designs in spinal device trials.
• To assess how often superiority claims arise post hoc from noninferiority studies.
• To critically evaluate the risk of bias associated with these superiority claims.

Main Methods:

• A systematic review of spinal device trials was conducted.
• The Cochrane Risk of Bias Tool was employed to assess study bias.
• Risk of bias for superiority claims was evaluated based on hypothesis specification, population analysis, outcome modification, and sensitivity analyses.

Main Results:

• Of 41 trials, 46% were noninferiority, 37% were noninferiority with secondary superiority hypotheses, and 17% were superiority trials.
• 14 (41%) of noninferiority trials made superiority claims, with 64% of these having medium or high risk of bias.
• Superiority claims in noninferiority trials were frequently associated with issues like analyzed population, sensitivity analyses, and modified endpoints.

Conclusions:

• Healthcare decision-makers must rigorously assess the risk of bias in superiority claims derived from spinal device trials.
• Conclusions drawn from noninferiority trials with post hoc superiority claims require cautious interpretation due to potential bias.