We thank Barlis and colleagues for their legitimate1 query about the ability of the propensity score regression technique to balance covariates between the somewhat heterogeneous groups. Our decision to report the results of a propensity score regression analysis conducted across the overall study population was based on a number of considerations. Nevertheless, application of propensity score matching (as suggested by Barlis and colleagues) in 2 well-balanced but smaller groups (253 patients each) substantially confirms the main results. Indeed, the result for the main …