TO THE EDITOR—We would like to commend Dr. Kofteridis and his colleagues for their recent excellent contribution to our understanding of treatment of multidrug-resistant Acintobacter [1]. Their investigation provides important data on the potential benefit of using aerosolized colistin for the treatment of ventilator-associated pneumonia due to multidrug-resistant organisms [1]. Although Kofteridis et al [1] conclude that the addition of aerosolized colistin did not provide therapeutic benefit, we favor Dr Patterson's interpretation that, “the combination of aerosolized plus intravenous colistin is potentially promising” [2, p. 1246]. Data from this investigation show a clear trend toward therapeutic benefit without a significant incidence of adverse events. In the Methods section, Kofteridis et al [1] comment that they collected data on prior and simultaneous use of antimicrobial agents. There are good data that suggest potential synergism between colistin and other antibiotic agents [3]. However, the use and distribution of simultaneous antimicrobial drugs was not described. Were there differences in antibiotic prescribing patterns between the 2 groups? Did the authors consider a secondary analysis to take into consideration the impact of additional therapy? This type of secondary or subgroup analysis has proven to be valuable in other similar studies [4]. We consider this article to be a timely and important addition to the medical literature. We are interested in seeing additional data, because they may improve our ability to interpret these results.