Odds and associated factors for thrombosis development among Lebanese COVID-19 patients: a case–control retrospective study

Figures & data

Figure 1. Types of thromboembolic events in hospitalised patients with COVID-19.

Table 1. Demographic and clinical characteristics of COVID patients with and without thromboembolic events.

Variable	Total (N = 267)	Case (N = 26)	Control (N = 241)	P-value
No. of patients, n (%)	267	26 (9.7)	241 (90.3)
Age, y (mean ± SD)	61.6 ± 15.4	62.6 ± 11.29	61.5 ± 15.8	0.730
Age group, y
≤45	41 (15.4)	3 (11.5.3)	38 (15.8)	0.764
46–64	98 (36.7)	11 (42.3)	87 (36.1)
≥65	128 (47.9)	12 (46.2)	116 (48.1)
Gender
Male	163 (61)	21 (80.8)	142 (58.9)	0.03
Female	104 (39)	5 (19.2)	99 (41.1)
BMI, (mean ± SD)	28.5 ± 4.6	29.9 ± 7.1	28.3 ± 4.2	0.365
BMI group, kg/m^2
<25	26 (19.5)	2 (12.5)	24 (20.5)	0.737
≥25	107 (80.5)	14 (87.5)	93 (79.5)
Co-morbidities
Coronary artery disease	94 (35.2)	9 (34.6)	85 (35.3)	0.947
Diabetes mellitus	95 (35.6)	12 (46.2)	83 (34.4)	0.236
Hypertension	115 (43.1)	17 (65.4)	98 (40.7)	0.016
Dyslipidaemia	36 (13.5)	6 (23.1)	30 (12.4)	0.136
Chronic kidney disease	24 (9.1)	4 (15.4)	20 (8.3)	0.269
Peripheral artery disease	17 (6.5)	2 (7.7)	15 (6.2)	0.675
Previous thromboembolic event	4 (1.5)	2 (7.7)	2 (0.8)	0.048
Medication history
Anti-platelet (aspirin)	85 (31.8)	12 (46.2)	73 (30.3)	0.099
Anti-hypertensive	96 (36)	16 (61.5)	80 (33.2)	0.004
Cholesterol-lowering	50 (18.7)	10 (38.5)	40 (16.6)	0.014
Anti-diabetics	91 (34.1)	11 (42.3)	80 (33.2)	0.352
Patient status during hospitalisation
Ambulatory	231 (86.5)	24 (92.3)	207 (85.9)	0.548
Immobile (bedridden)	36 (13.5)	2 (7.7)	34 (14.1)
Disease severity
Critical COVID-19	87 (32.6)	16 (61.5)	71 (29.5)	0.004
Severe COVID-19	24 (9)	1 (3.8)	23 (9.5)
Non-severe COVID-19	156 (58.4)	9 (34.6)	147 (61)

*Data are presented as mean ± standard deviation for continuous variables and number (%) for categorical variables.

This study elected to use the WHO severity definitions based on clinical indicators, adapted from WHO COVID-19 disease severity categorisation.

Numbers in bold indicate significant p-values.

Table 2. Laboratory data of COVID-19 patients with and without thromboembolic events.

Variable	Case (N = 26)	Control (N = 241)	P-value
D-dimer, ng/ml	5932 ± 6927.1	3097 ± 3041.0	0.093
Normal	1 (5.3)	10 (4.9)	0.948
Elevated	18 (94.7)	193 (95.1)
CRP, mg/dl	114.9 ± 131.1	35.6 ± 68.6	0.007
Normal	1 (3.8)	2 (0.9)	0.274
Elevated	25 (96.2)	230 (99.1)
Ferritin, ng/ml	3527.3 ± 5837.2	1297.6 ± 2113.5	0.106
Normal	1 (5)	19 (9.2)	1.000
Elevated	15 (95)	188 (90.8)
Serum Creatinine, mg/dl	2.6 ± 2.5	1.6 ± 1.5	0.052
Normal	12 (46.2)	156 (64.7)	0.062
Elevated	14 (53.8)	85 (35.3)
Haematocrit, %	36.8 ± 8.2	35.5 ± 5.9	0.442
Normal	6 (24)	59 (24.7)	0.940
Low	19 (76)	180 (75.3)
Haemoglobin, g/dl	11.9 ± 2.7	11.9 ± 2.4	0.951
Normal	10 (40)	99 (41.3)	0.904
Low	15 (60)	141 (58.7)
Platelets, k/µl	188.7 ± 95.8	228.8 ± 95.6	0.047
Low	10 (40)	34 (14.5)	0.003
Normal	15 (60)	201 (85.5)
Oxygen saturation,%	88.7 ± 9.8	89.5 ± 8.9	0.677
Normal	11 (44)	83 (36.6)	0.466
Low	14 (56)	144 (63.4)

*Data are presented as mean ± standard deviation for continuous measures and number (%) for categorical variables.

Reference normal ranges for each parameter: D-dimer (<250 ng/ml), CRP (0-0.6 mg/dl), Ferritin (4.63–204 ng/ml), Cr (0.5–1.3 mg/dl), Haematocrit (Females: 37%–47%; Males: 42%–52%), Haemoglobin (Females: 12–16 g/dl; Males: 13.5–18 g/dl), Platelets (140–440 k/µl), oxygen saturation PO₂ (≥93%).

Numbers in bold indicate significant p-values.

Table 3. Treatments, complications, and hospital status.

Variable	Total (N = 267)	Case (N = 26)	Control (N = 241)	P-value
Complications
Oxygen therapy	236 (88.4)	20 (76.9)	216 (89.6)	0.097
Mechanical ventilation	81 (30.3)	16 (61.5)	65 (27)	<0.001
Acute respiratory distress syndrome	36 (13.7)	1 (5.3)	35 (14.3)	0.486
Bleeding event	16 (6)	7 (26.9)	9 (3.7)	<0.001
Hospital floor
Intensive care unit (ICU)	109 (40.8)	19 (73.1)	90 (37.3)	<0.001
Baseline anticoagulation
None	15 (5.6)	0	15 (6.2)	<0.001
Prophylactic anticoagulation	198 (74.2)	10 (38.5)	188 (78)
Therapeutic anticoagulation	54 (20.2)	16 (61.5)	38 (15.8)
Type of anticoagulant
Low molecular weight heparin (LMWH)	113 (42.3)	15 (57.7)	98 (40.7)	0.122
Heparin	112 (41.9)	11 (42.3)	101 (41.9)
Direct oral anticoagulants (DOAC)	27 (10.1)	0	27 (11.2)
In hospital anti-platelet	140 (83.8)	19 (86.4)	121 (83.4)	1.000
Length of hospital stay	10.8 ± 8.2	11.2 ± 7.4	10.8 ± 8.3	0.826
Clinical outcome
Discharged	143 (53.6)	2 (7.7)	141 (58.5)	<0.001
Still at hospitalised at the time of study conductance	37 (13.9)	6 (23.1)	31 (12.9)
Inpatient death	87 (32.6)	18 (69.2)	69 (28.6)

*Data are presented as mean ± standard deviation for continuous measures and number (%) for categorical measures.

Numbers in bold indicate significant p-values.

Table 4. Multivariate logistic regression models: risk factors associated with thromboembolic events development in hospitalised COVID-19 patients.

	B	P-value	Exp (B)	95% C.I. for Exp (B)
			OR	Lower	Upper
Gender (females to males*)	−1.108	0.035	0.3	0.118	0.925
Anti-hypertensives (Yes to No*)	1.137	0.009	3.1	1.326	7.327
Prophylactic anticoagulation (Yes vs No*)	−2.069	<0.001	0.1	0.053	0.300
Disease severity (non-severe vs critical COVID-19*)	−1.298	0.004	0.3	0.114	0.656
Previous thromboembolic event (Yes vs No*)	2.215	0.040	9.2	1.108	75.707
Hospital discharge (Yes vs No*)	−2.565	0.001	0.1	0.017	0.352

Variables entered: gender, anti-platelet (aspirin) at home, cholesterol lowering medications at home, anti-hypertensive medications at home, type of anticoagulant used at hospital, oxygen therapy, mechanical ventilation, bleeding events, baseline anticoagulation upon hospital admission, hypertension, dyslipidaemia, previous thromboembolic event, COVID severity (critical, severe and non-severe COVID-19), ICU admission, clinical outcome (discharged, still at hospital, inpatient death).

*Reference group.

Data availability statement

All data generated or analysed during this study are not publicly available to maintain the privacy of the individuals’ identities. The dataset supporting the conclusions is available upon request to the corresponding author.