Comment on: Margolis et al. Lack of Effectiveness of Hyperbaric Oxygen Therapy for the Treatment of Diabetic Foot Ulcer and the Prevention of Amputation: A Cohort Study. Diabetes Care 2013;36:1961–1966

I read with interest and some disbelief the article by Margolis et al. (1), who conclude that “the usefulness of [hyperbaric oxygen (HBO)] in the treatment of diabetic foot ulcers needs to be reevaluated.” Statistical manipulation cannot change the big problem with the study design. Propensity score matching is a technique to be used in situations with substantial overlap between treatment and control groups to account for observed covariates. Factors that affect assignment to treatment but that cannot be observed (e.g., financial gain, clinician preference, lack of vascular surgical input, etc.) cannot be accounted for. It has been argued that this technique may increase hidden …