Preventing confounding in observational studies in orthopedic trauma surgery through expert panels: a systematic review.

Purpose: Confounding in observational studies can be mitigated by selecting only those patients, in whom equipoise of both treatments is secured by experts' disagreement over optimal therapy.

Methods: We conducted a systematic review to identify observational studies in the field of orthopedic trauma surgery that utilized expert panels for patient inclusion in order to limit the potential for confounding.

Results: Four studies were identified that used expert panels to select participants based on expert disagreement. Derived from these studies and our own experience, recommendations were made regarding reporting of the size and composition of the expert panel, the information the expert panel receives, criteria for disagreement, selection of patients, and statistical analysis.

Conclusion: With this review we aim to provide insight into this study design and to stimulate discussions about the potential of expert panels to control for confounding in studies of medical treatments.