Table 2– Results of receiver operating characteristic (ROC) curve analysis

	Prediction of mortality			Prediction of any adverse outcomes			Prediction of ICU admission			Prediction of complications
	AUC (95% CI)	p-value versus PSI	p-value versus CURB-65	AUC (95% CI)	p-value versus PSI	p-value versus CURB-65	AUC (95% CI)	p-value versus PSI	p-value versus CURB-65	AUC (95% CI)	p-value versus PSI	p-value versus CURB-65
PSI score	0.79 (0.75–0.84)		0.008	0.67 (0.62–0.71)		0.26	0.65 (0.59–0.71)		0.7	0.50 (0.40–0.60)		0.93
CURB-65 score	0.72 (0.65–0.78)	0.008		0.64 (0.60–0.69)	0.26		0.64 (0.58–0.70)	0.70		0.50 (0.41–0.60)	0.93
Initial PCT levels	0.60 (0.52–0.67)	<0.001	<0.01	0.66 (0.61–0.71)	0.82	0.63	0.69 (0.64–0.75)	0.27	0.14	0.69 (0.58–0.77)	<0.01	<0.01
Peak PCT levels	0.65 (0.57–0.72)	<0.01	0.13	0.69 (0.65–0.74)	0.40	0.1	0.73 (0.67–0.79)	0.035	0.01	0.7 (0.59–0.80)	<0.01	<0.01
Combined initial PCT/PSI score	0.80 (0.74–0.85)	0.91		0.71 (0.66–0.76)	<0.01		0.72 (0.67–0.78)	<0.01		0.68 (0.58–0.77)	<0.01
Combined initial PCT/CURB-65 score	0.73 (0.66–0.79)		0.43	0.70 (0.65–0.75)		0.008	0.71 (0.65–0.77)		<0.01	0.68 (0.58–0.78)		<0.01

ICU: intensive care unit; AUC: area under the ROC curve; PSI: Pneumonia Severity Index;; CURB-65: confusion, urea >7 mmol·L⁻¹, respiratory frequency ≥30 breaths·min⁻¹, low blood pressure (systolic value <90 mmHg or diastolic value ≤60 mmHg) and age ≥65 yrs; PCT: procalcitonin.