Table 6.

Population and outcomes stratification according to the risk of early ICU admission index (REA-ICU index) of patients with community acquired pneumonia

		Derivation population			Validation population
Risk class	Score	N	ICU ≤ 3 days, % (95% CI)	Death ≤ 28 days, % (95% CI)	n	ICU ≤ 3 days, % (95% CI)	Death ≤ 28 days, % (95% CI)
I	≤ 3	2510	1.1 (0.7 to 1.6)	1.2 (0.8 to 1.8)	1099	1.3 (0.7 to 2.1)	1.9 (1.2 to 2.9)
II	4 to 6	1498	5.5 (4.4 to 6.8)	6.0 (4.8 to 7.3)	633	7.1 (5.2 to 9.4)	4.4 (3.0 to 6.3)
III	7 to 8	419	11.0 (8.2 to 14.4)	9.1 (6.5 to 12.2)	164	12.2 (7.6 to 18.2)	7.9 (4.2 to 13.2)
IV	≥ 9	166	27.1 (20.5 to 34.5)	15.1 (10.0 to 21.4)	71	32.4 (21.7 to 44.5)	22.5 (13.5 to 34.0)
Total		4593	4.4 (6.0 to 7.4)	4.0 (3.4 to 4.6)	1967	5.2 (5.8 to 8.0)	4.0 (3.1 to 4.9)

ICU ≤ 3 days and death ≤ 28 days refer to patients who were admitted to an ICU within three days of presentation to the emergency department or who died within 28 days of presentation, respectively. Results are expressed as percentages of each outcome within each REA-ICU risk class. CI = confidence interval; ICU = intensive care unit.