Table 3.

Baseline characteristics between patients with acute respiratory distress syndrome (ARDS) and controls and survivors and nonsurvivors in ARDS

	Development of ARDS			Mortality in ARDS
	Controls (n = 442)	Cases (n = 212)	p Value	Survivors (n = 114)	Nonsurvivors (n = 98)	p Value
Females, n (%)	179 (41)	101 (48)	.09	50 (44)	51 (52)	.3
Age, median (range)	69 (18-94)	65 (18-97)	.05	57 (18-89)	73 (22-97)	<.001
APACHE III median (range)^a	64 (14-130)	68 (8-136)	.08	69 (8-115)	88 (29-150)	<.001
Diabetes, n (%)^b	116 (26)	34 (16)	.004	20 (18)	14 (14)	.6
History of alcohol abuse, n (%)	42 (10)	27 (13)	.2	10 (9)	17 (17)	.07
Tobacco abuse, n (%)^c	217 (49)	105 (50)	.4	57 (50)	48 (49)	.7
Chronic liver disease, n (%)^b	18 (4)	12 (6)	.4	4 (4)	8 (8)	.2
End-stage renal disease, n (%)	23 (5)	6 (3)	.2	2 (2)	4 (4)	.4
History of steroid use, n (%)	37 (8)	20 (9)	.7	6 (5)	14 (14)	.03
Transfusion of PRBC, n (%)	218 (49)	133 (63)	.001	64 (56)	69 (70)	.03
Number of PRBC transfused, median (range)	0 (0-74)	2 (0-63)	.005	1 (0-31)	2 (0-63)	.01
Systolic BP <90 mm Hg, n (%)	305 (69)	163 (77)	.04	85 (75)	78 (80)	.4
Creatinine <2.0 mg/L, n (%)	150 (34)	65 (31)	0.4	28 (25)	37 (38)	.05
Bilirubin <2.0 mg/dL, n (%)	53 (12)	39 (18)	.03	14 (12)	25 (26)	.02
Hematologic failure (platelets ≤80,000/mm), n (%)	60 (14)	47 (22)	.007	20 (18)	27 (28)	.1

APACHE, Acute Physiology and Chronic Health Evaluation; PRBC, packed red blood cells; BP, blood pressure.

For development of ARDS, APACHE III scores for patients and controls were calculated without the PaO₂/FIO₂ component; for survivors and nonsurvivors in ARDS, APACHE III scores were calculated with all components

chronic health information was missing on one patient and two controls

tobacco history was missing in 56 (26%) patients and 97 (22%) controls.