Table 2. Prediction performance.

Abbreviations: AUROC = area under the receiver operating characteristic curve, PPV = positive pressure ventilation, NPV = negative predictive value.

Adverse event	Hospitalization, ICU, Intubation, or death	ICU, Intubation, or death	Death
Concurrent validation (based on the development cohort but cross-validated)
Number of patients (n, %)	3344 (35.6%)	782 (8.3%)	103 (1.1%)
Calibration (E/O)	1.00 [0.98, 1.02]	1.00 [0.93, 1.06]	1.00 [0.84, 1.21]
Calibration slope (CS)	0.99 [0.98, 0.99]	0.97 [0.96, 0.99]	n.c
AUC	0.80 [0.80, 0.81]	0.82 [0.80, 0.83]	0.87 [0.83, 0.91]
Spec. at 90% Sens.	0.56 [0.53, 0.59]	0.44 [0.41, 0.48]	0.35 [0.24, 0.45]
PPV at 90% Sens.	0.47 [0.45, 0.49]	0.16 [0.14, 0.17]	0.03 [0.02, 0.04]
NPV at 90% Sens.	0.89 [0.88, 0.90]	0.98 [0.98, 0.99]	1.00 [1.00, 1.00]
Prospective validation
Number of patients (n, %)	726 (32.9%)	151 (6.8%)	12 (0.54%)
Calibration (E/O)	1.01 [0.96, 1.07]	1.03 [0.89, 1.20]	1.63 [1.03, 3.25]
Calibration slope (CS)	0.99 [0.98, 1.00]	0.98 [0.96, 0.99]	n.c
AUC	0.76 [0.73, 0.78]	0.79 [0.75, 0.82]	0.93 [0.86, 0.98]
Spec. at 90% Sens.	0.66 [0.62, 0.70]	0.53 [0.43, 0.63]	0.29 [0.01, 0.31]
PPV at 90% Sens.	0.40 [0.38, 0.43]	0.11 [0.09, 0.14]	0.017 [0.01, 0.22]
NPV at 90% Sens.	0.87 [0.86, 0.89]	0.98 [0.98, 0.99]	1.00 [1.00, 1.00]

+ 95% confidence interval

PPV = positive predictive value, NPV = negative predictive value, Spec = specificity, Sens = sensitivity, ICU = intensive care unit, E/O = ratio of Expected to number of Observed adverse events, n.c. = not calculated due to small sample size.