Fig. 3.

Predicted probability of obtaining a BAL of good quality according to the amount of BAL fluid recovered in the whole study population. BAL bronchoalveolar lavage. For this estimation of the probability of obtaining a BAL of good quality, logistic regression adjusted for all covariables (see Table S6 in Online Resource 1) was used. The amount of BAL fluid recovered was transformed in cubic splines to account for non-linearity. The biphasic shape of the figure shows that below 60 mL of BAL fluid recovered, the estimated probability declines in parallel with the amount of fluid recovered