Finally, we disagree that clinicians do not need to understand the overall efficacy of a drug in the treatment of NP, including cases due to Gram-positive pathogens. At the present time, treatment of NP is largely empirical and clinicians do not know the causative pathogen at the time of diagnosis. The overall efficacy of a drug in treating NP is just as important as the efficacy in specific subsets of patients, as clinicians initially will not know the causative pathogen. As the authors note in their article,1 initial prescribing of an inappropriate drug in NP has been associated with increased mortality. The question of whether linezolid has superior efficacy in the treatment of NP due to MRSA can be answered by a prospective, randomized, controlled trial, and we applaud the sponsor of the drug for pursuing such a trial. However, until we have diagnostic testing that can quickly and easily determine the causative pathogen prior to initiation of treatment, it is unclear how this knowledge will aid the clinician when empirically prescribing drugs for NP. The authors assume that a larger trial would not show linezolid to be less effective for pathogens other than MRSA. For example, in trials in sepsis, follow-up trials of patients treated with an experimental monoclonal antibody did not confirm the efficacy seen in initial trials in subgroups of patients with Gram-negative bacteremia.9 In the setting of empirical treatment, with NP due to various pathogens, linezolid was found to be noninferior to vancomycin. The “hard” data show no difference in the proportions of clinical successes as defined in the study in the overall population of patients enrolled. This is the most relevant clinical question and the one that clinicians must grapple with at the bedside.