We thank Dr Boshuizen and colleagues for sharing their data and are glad to read that they had similar findings in their cohort. Importantly, they also found that only about one-half (45% in their study and 54% in ours) of the patients with MPE underwent definitive treatment, further highlighting the usefulness of a predictive tool. Dr Boshuizen and colleagues also found a higher pleural fluid protein level to be a predictor, similar to our finding on univariate analysis (OR, 1.03; P < .05). Both studies also identified age as a (weak) predictor. Our study identified pleural fluid pH as the most important predictor. Unfortunately, pH was not captured in the study of Dr Boshuizen and colleagues.