If the aforementioned study is included in the meta-analysis, as shown in Figure 1,2-7 the relative risk of clinical success of the patients who received linezolid will become 1.23 (95% CI, 1.06-1.45; P = .009). Therefore, linezolid is statistically more effective than vancomycin for the treatment of proven MRSA nosocomial pneumonia. It should be kept in mind, however, that linezolid must be prescribed to patients with suspected MRSA nosocomial pneumonia, and only 30% to 40% of patients suspected of having MRSA pneumonia actually have proven MRSA pneumonia. Moreover, although the pooled estimate of a difference in efficacy of linezolid over vancomycin from our meta-analysis is 10.8%, the 95% CI of such a difference is 3.2% to 18.5%. Therefore, a cost-effectiveness analysis should be performed to determine if linezolid is efficient for empirical therapy of suspected MRSA nosocomial pneumonia and for specific therapy of proven MRSA nosocomial pneumonia.