Association Between Blood Eosinophils and Mortality in Critically Ill Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Retrospective Cohort Study

Figures & data

Table 1 Comparisons of Demographic Characteristics Between Survivors and Non-Survivors

Variables	Total (n=1019)	Survivors (n=887)	Non-Survivors (n=132)	p
Male	510 (50.0)	443 (49.9)	67 (50.8)	0.861
Age, yr	72.4 (64.3,80.6)	71.2 (63.7,79.7)	79.0 (72.3,83.4)	<0.001
Ethnicity				0.021
White	776 (76.2)	669 (75.4)	107 (81.1)
Black	141 (13.8)	132 (14.9)	9 (6.8)
Hispanic	23 (2.3)	22 (2.5)	1 (0.8)
Asian	16 (1.6)	12 (1.4)	4 (3.0)
Other	63 (6.2)	52 (5.9)	11 (8.3)
Admission type				1.000
Elective	4 (0.4)	4 (0.5)	0
Emergency	1004 (98.5)	873 (98.4)	131 (99.2)
urgent	11 (1.1)	10 (1.1)	1 (0.8)
Comorbidities
Asthma	5 (0.5)	5 (0.6)	0 (0)	1.000
Pneumonia
Bacterial pneumonia	144 (14.1)	121 (13.6)	23 (17.4)	0.244
Viral pneumonia	4 (0.4)	4 (0.5)	0 (0)	1.000
Pneumonia, unclassified	326 (32.0)	274 (30.9)	52 (39.4)	0.051
Ventilator-associated pneumonia	15 (1.5)	11 (1.2)	4 (3.0)	0.228
Congestive heart failure	522 (51.2)	449 (50.6)	73 (55.3)	0.315
Cardiac arrhythmias	422 (41.4)	339 (38.2)	83 (62.9)	<0.001
Valvular disease	139 (13.6)	118 (13.3)	21 (15.9)	0.416
Pulmonary circulation	142 (13.9)	131 (14.8)	11 (8.3)	0.046
Hypertension	599 (58.8)	526 (59.3)	73 (55.3)	0.384
Diabetes	295 (28.9)	267 (30.1)	28 (21.2)	0.036
Renal failure	175 (17.2)	146 (16.5)	29 (22.0)	0.117
Liver disease	50 (4.9)	38 (4.3)	12 (9.1)	0.017
Solid tumor	48 (4.7)	37 (4.2)	11 (8.3)	0.035
Metastatic cancer	40 (3.9)	28 (3.2)	12 (9.1)	0.001
Other neurological	94 (9.2)	80 (9.0)	14 (10.6)	0.557
Mechanical ventilation
Invasive	156 (15.3)	138 (15.6)	18 (13.6)	0.567
Non-invasive	118 (11.6)	103 (11.6)	15 (11.4)	0.934
Eosinophils, %
Eosinophil initial	0.5 (0.1,1.5)	0.6 (0.1,1.6)	0.2 (0,0.875)	<0.001
Eosinophil max	1.0 (0.3,2.1)	1.0 (0.3,2.2)	0.7 (0.1,2.0)	0.001
Eosinophil mean	0.5 (0.2,1.4)	0.6 (0.2,1.4)	0.3 (0.1,0.8)	<0.001
Neutrophils, %	83.0 (74.8,89.7)	82.8 (74.3,89.4)	85.6 (78.6,92.0)	0.003
Lymphocytes, %	9.7 (5.2,15.4)	10.0 (5.5,15.9)	7.0 (3.6,12.4)	<0.001
Systemic corticosteroid treatment	844 (82.8)	735 (82.9)	109 (82.6)	0.935
Antibacterial treatment	909 (89.2)	786 (88.6)	123 (93.2)	0.115
SAPS II	37 (29,45)	35 (29,43)	47 (39,59)	<0.001
SOFA score	3 (2,5)	3 (2,5)	6 (4,8)	<0.001
PaO2, mmHg	87 (69,131)	87 (69,127)	87 (69,138)	0.652
PaCO2, mmHg	56 (46,72)	56 (47,72)	55 (41,73)	0.143
ph	7.34 (7.27,7.39)	7.34 (7.27,7.39)	7.32 (7.24,7.39)	0.207
Hospital LOS, day	7.2 (4.5,12.0)	7.1 (4.8,11.8)	7.5 (3.3,13.9)	0.387
ICU LOS, day	3.0 (1.5,6.0)	2.9 (1.5,5.7)	4.1 (1.8,9.3)	<0.001

Notes: Eosinophil _initial was defined as the first value of blood eosinophil concentrations measured in the stage between 24 hours before admission and 24 hours after admission. Eosinophil _max was defined as the maximum value during the hospitalization. Eosinophil _mean was defined as the arithmetic mean of all values during hospitalization.

Abbreviations: SOFA, sequential organ failure assessment; SAPS, simplified acute physiology score; LOS, length of stay.

Figure 1 Flowchart of patient selection.

Table 2 ORs of Eosinophil_initial for Outcomes

Outcomes	Univariate Model		Multivariate Model 1		Multivariate Model 2
	OR	p	OR	p	OR	p
In-hospital mortality	0.719 (0.592–0.873)	0.001	0.792 (0.643–0.976)	0.028	0.785 (0.636–0.968)	0.024
In-ICU mortality	0.746 (0.603–0.923)	0.007	0.812 (0.645–1.022)	0.076	0.807 (0.641–1.016)	0.068
Hospital length of stay (>7days)	0.849 (0.781–0.924)	<0.001	0.847 (0.772–0.930)	0.001	0.854 (0.778–0.939)	0.001
ICU length of stay (>3days)	0.882 (0.814–0.957)	0.003	0.914 (0.836–1.000)	0.049	0.917 (0.838–1.004)	0.060

Notes: Multivariate model 1: adjusted for SAPS II score, cardiac arrhythmias, solid tumor, metastatic cancer, liver disease, neutrophils (%), and mean VIF was 1.09 for in-hospital mortality. Multivariate model 2: adjusted for SOFA score, age, cardiac arrhythmias, solid tumor, metastatic cancer, liver disease, neutrophils (%), and mean VIF was 1.10 for in-hospital mortality.

Figure 2 Receiver operating characteristic (ROC) curve for the prediction of in-hospital mortality in critically ill patients with AECOPD by eosinophil concentrations.