Figure 4.

Timing of ICU admission relative to clinical risk and diagnosis of lung injury. Frequency histograms are shown for the timing of intensive care unit (ICU) admission relative to development of clinical risk condition (a), and diagnosis of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) relative to ICU admission (b), including together all patients with ALI and ARDS admitted to the ICU. Dx, diagnosis; IQR, interquartile range.