W read with interest the recent article by Hasley et al,1 in which they found that bilateral pleural effusions were independently associated with 30-day mortality, with a relative risk of 2.8. This is a very well done and interesting study. As a clinician seeing patients in various settings, the question that was not directly addressed in the study, but for which the authors clearly have the data, is how much does the presence of bilateral effusion on the chest radiographic examination increase the risk of 30-day mortality compared with other well-known risk factors. For example, in deciding about admitting a patient, clinicians are well aware of the importance of hypoxia, age, comorbid conditions, sepsis, and multiorgan failure as prognostic findings. How did the relative risk of death for the variable "bilateral pleural effusion," in the author's multivariate model, compare with the relative risk of death from other, traditional risk