Table 4– Performance of Lung Injury Prediction Study (LIPS) in the two cohorts

	Retrospective derivation cohort: ICU	Prospective validation cohort: hospital
Incidence of ALI/ARDS	0.17 (68/409)	0.07 (32/463)
AUC (95% CI)	0.84 (0.80–0.89)	0.84 (0.76–0.92)
Sensitivity (95% CI), LIPS>3	0.41 (0.32–0.50)	0.69 (0.53–0.82)
Specificity (95% CI), LIPS>3	0.90 (0.89–0.92)	0.84 (0.83–0.85)
Positive predictive value (95% CI), LIPS>3	0.46 (0.36–0.56)	0.24 (0.18–0.28)
Positive likelihood ratio (95% CI), LIPS>3	4.26 (2.77–6.41)	4.27 (3.03–5.39)
Negative likelihood ratio (95% CI), LIPS>3	0.65 (0.54–0.77)	0.37 (0.22–0.56)

ICU: intensive care unit; ALI: acute lung injury; ARDS: acute respiratory distress syndrome; AUC: area under the curve.