The Reply

We read with interest the letter to the editor by Prof. Kawada, and appreciate the points that were raised. First, we agree that we did not adjust for severity of chronic obstructive pulmonary disease (COPD) in our analysis of administrative claims data.1 Inability to adjust for severity of disease is a known limitation of such administrative claims analysis.2 However, it is for that reason that we adjusted for concomitant medications and propensity scores — which, although it is not the same as severity assessment using spirometry or imaging — offers a means to account for severity of COPD.
Source: The American Journal of Medicine - Category: General Medicine Authors: Tags: Letter Source Type: research