We thank Drs Desai and El Solh for their letter about our article in CHEST (December 2009)1 addressing the association between ICU admission during morning round time and mortality. In our study, we created a multiple logistic regression model by entering admission source, Acute Physiology and Chronic Health Evaluation (APACHE) III-predicted mortality rate, and intensity of treatment. Drs Desai and El Solh highlight that such an approach may lead to colinearity, resulting in imprecise estimates of regression coefficients and reduced tests of significance. In addition to several other variables, the APACHE III prognostic model includes the patient’s location before ICU admission as one of the predictor variables.2 The intensity of treatment is also greatly influenced by the severity of illness, measured by the APACHE III prognostic model.3 We share the concern raised by Drs Desai and El Solh. In a previous study, we tried to customize the APACHE III prognostic model to our patient population.4 In that study, the addition of the ICU admission source and intensity of treatment improved the mortality prediction, leading us to include them in our recent study in CHEST. Because of the colinearity concern raised in the letter, we performed a multiple logistic regression analysis without including the intensity of treatment and the source of admission as predictor variables. The observed association between admission during rounding time and risk of death remained significant, with an odds ratio (95% CI) of 1.644 (range, 1.466-1.842) and P < .001.