Week-One Anaemia was Associated with Increased One-Year Mortality in Critically Ill Surgical Patients

Table 1

Characteristics between the patients categorised by week-1 level of haemoglobin in the primary cohort and propensity score-matched cohort.

	Before PSM			1 : 1 PSM
	Hb < 10	Hb ≥ 10	SMD	Hb < 10	Hb ≥ 10	SMD
	n = 2.280	n = 5.343		n = 1.501	n = 1.501
Basic characteristics
Age, years	64.4 ± 16.3	59.6 ± 15.7	0.304	63.3 ± 16.5	63.2 ± 15.6	0.007
Sex (male)	1422 (62.4%)	3423 (64.1%)	0.035	946 (63.0%)	946 (63.0%)	<0.001
Body mass index	23.8 ± 4.6	24.4 ± 4.5	0.140	23.9 ± 4.6	23.8 ± 4.6	0.022
Charlson comorbidity index	2.0 ± 1.6	1.4 ± 1.3	0.410	1.8 ± 1.5	1.8 ± 1.5	0.025
Severity and managements
APACHE II score	22.7 ± 6.6	19.6 ± 5.9	0.505	21.6 ± 6.4	21.2 ± 6.0	0.057
Presence of shock	1147 (50.3%)	1353 (25.3%)	0.533	663 (44.2%)	663 (44.2%)	<0.001
Emergent surgery	183 (8.0%)	106 (2.0%)	0.280	69 (4.6%)	71 (4.7%)	0.006
Surgical divisions
Cardiovascular surgery	456 (20.0%)	811 (15.2%)	0.127	386 (25.7%)	386 (25.7%)	<0.001
Neurosurgery	263 (11.5%)	2293 (42.9%)	0.753	246 (16.4%)	246 (16.4%)	<0.001
Major abdomen surgery	328 (14.4%)	172 (3.2%)	0.402	132 (8.8%)	132 (8.8%)	<0.001
Others	495 (21.7%)	558 (10.4%)	0.310	300 (20.0%)	281 (18.7%)	0.032
Blood loss at operating room, ml	404.8 ± 612.6	326.2 ± 527.9	0.137	463.1 ± 633.1	464.5 ± 649.3	0.002
Receiving RBC transfusion	1890 (82.9%)	1785 (33.4%)	1.160	1132 (75.4%)	1110 (74.0%)	0.034
Receiving mechanical ventilation	1771 (77.7%)	3500 (65.5%)	0.272	1133 (75.5%)	1174 (78.2%)	0.065
Receiving RRT	362 (15.9%)	108 (2.0%)	0.500	122 (8.1%)	99 (6.6%)	0.059
End-stage renal disease	92 (4.0%)	25 (0.5%)	0.242	31 (2.1%)	23 (1.5%)	0.040
Fluid balance day 1–3	1649.9 ± 3010.0	659.7 ± 2062.9	0.384	1435.1 ± 2805.6	1159.2 ± 2474.7	0.104
Positive microbiological culture	1161 (50.9%)	1404 (26.3%)	0.523	675 (45.0%)	640 (42.6%)	0.047
Laboratory data
White blood cell count (10 [3]/μl)	11049.6 ± 5620.9	10792.5 ± 3888.1	0.053	10903.7 ± 5198.4	11147.5 ± 4159.1	0.052
Platelet (10 [3]/μL)	167.6 ± 99.8	206.6 ± 80.7	0.430	173.7 ± 100.2	178.5 ± 87.4	0.052
Albumin (mg/dL)	3.0 ± 0.7	3.7 ± 0.7	0.936	3.2 ± 0.7	3.2 ± 0.7	0.040
Creatinine (mg/dL)	2.0 ± 2.1	1.0 ± 0.9	0.607	1.6 ± 1.8	1.3 ± 1.4	0.236
Outcome
ICU length of stay, days	12.1 ± 13.5	7.6 ± 10.2	0.377	10.5 ± 12.5	10.4 ± 13.8	0.011
Hospital length of stay, days	29.95 ± 27.8	19.3 ± 23.5	0.409	26.1 ± 23.5	26.6 ± 33.3	0.017
One-year mortality	958 (42.0%)	924 (17.3%)	0.562	535 (35.6%)	442 (29.4%)	0.133

Data are shown as mean ± standard deviation and number (percentages). PSM, propensity score-matching; SMD, standard mean difference; Hb, haemoglobin (g/dL); APACHE, Acute Physiology and Chronic Health Evaluation; RBC, red blood cell; RRT, renal replacement therapy; ICU, intensive care unit.