We thank Drs BaHammam and Esquinas Rodriguez for their letter about our recent study.1 As they correctly note, the prevalence of obesity (as reflected by International Classification of Diseases, Ninth Revision, codes) was roughly six times higher among patients with OSA than in those without OSA. Given the high potential for obesity to serve as a confounder, our multivariable analyses included obesity as a covariate, thereby yielding an estimate of the independent association between OSA and the two outcomes we studied: (1) in-hospital mortality and (2) initiation of mechanical ventilation or transfer to the ICU after the second hospital day (a measure of clinical deterioration). In light of the comments by Drs BaHammam and Esquinas Rodriguez, it is also worth noting that in the multivariable analyses (presented in e-Tables 2 and 3 of our article), obesity remained associated with lower in-hospital mortality. However, obesity was not associated with late mechanical ventilation in these analyses. Finally, although we did not include these results in the article, we also investigated the possibility of an interaction between obesity and OSA. The P value for the interaction term was .81, suggesting that patients with OSA and obesity had similar outcomes to patients with OSA who were not obese.