J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website https://www.jocmr.org

Original Article

Volume 12, Number 12, December 2020, pages 809-815

Analysis of ABO and Rh Blood Type Association With Acute COVID-19 Infection in Hospitalized Patients: A Superficial Association Among a Multitude of Established Confounders

**Table 1.** Demographics and ABO/Rh Distribution of the Overall Study Population and Between Control and COVID-19 Populations
	General population	COVID-19-positive	Control population	P value
*Denotes statistical significance. SD: standard deviation; COVID-19: coronavirus disease 2019.
Frequency (n)	1,221	825	396
Age, mean ± SD	56.53 ± 19.19	57.64 ± 18.17	54.21 ± 20.99	0.005*
Sex, n (%)				< 0.001*
Female	546 (44.7%)	325 (39%)	221 (56%)
Male	675 (55.3%)	500 (61%)	175 (44%)
COVID-19 positive, n (%)
No (control)	396 (32.4%)
Yes	825 (67.6%)
Mortality
Deceased on discharge, n (%)		278 (33.7%)
Blood type, ABO/Rh, n (%)				0.018*
A/Rh-negative	21 (2%)	17 (2%)	4 (1%)
A/Rh-positive	286 (23%)	203 (25%)	83 (21%)
AB/Rh-negative	1 (0%)	1 (0%)	0 (0%)
AB/Rh-positive	49 (4%)	26 (3%)	23 (6%)
B/Rh-negative	8 (1%)	5 (1%)	3 (1%)
B/Rh-positive	179 (15%)	107 (13%)	72 (18%)
O/Rh-negative	31 (3%)	17 (2%)	14 (4%)
O/Rh-positive	646 (53%)	449 (54%)	197 (50%)
ABO blood type, n (%)				0.007*
A	307 (25.1%)	220 (26.7%)	87 (22.0%)
AB	50 (4.1%)	27 (3.3%)	23 (5.8%)
B	187 (15.3%)	112 (13.6%)	75 (18.9%)
O	677 (55.4%)	466 (56.5%)	211 (53.3%)
Rh blood type, n (%)				0.733
Negative	61 (5.0%)	40 (4.8%)	21 (5.3%)
Positive	1,160	785 (95.2%)	375 (94.7%)

Table 1. Demographics and ABO/Rh Distribution of the Overall Study Population and Between Control and COVID-19 Populations

General population

COVID-19-positive

Control population

P value

*Denotes statistical significance. SD: standard deviation; COVID-19: coronavirus disease 2019.

Frequency (n)

1,221

825

396

Age, mean ± SD

56.53 ± 19.19

57.64 ± 18.17

54.21 ± 20.99

0.005*

Sex, n (%)

< 0.001*

Female

546 (44.7%)

325 (39%)

221 (56%)

Male

675 (55.3%)

500 (61%)

175 (44%)

COVID-19 positive, n (%)

No (control)

396 (32.4%)

Yes

825 (67.6%)

Mortality

Deceased on discharge, n (%)

278 (33.7%)

Blood type, ABO/Rh, n (%)

0.018*

A/Rh-negative

21 (2%)

17 (2%)

4 (1%)

A/Rh-positive

286 (23%)

203 (25%)

83 (21%)

AB/Rh-negative

1 (0%)

0 (0%)

AB/Rh-positive

49 (4%)

26 (3%)

23 (6%)

B/Rh-negative

8 (1%)

5 (1%)

3 (1%)

B/Rh-positive

179 (15%)

107 (13%)

72 (18%)

O/Rh-negative

31 (3%)

17 (2%)

14 (4%)

O/Rh-positive

646 (53%)

449 (54%)

197 (50%)

ABO blood type, n (%)

0.007*

307 (25.1%)

220 (26.7%)

87 (22.0%)

50 (4.1%)

27 (3.3%)

23 (5.8%)

187 (15.3%)

112 (13.6%)

75 (18.9%)

677 (55.4%)

466 (56.5%)

211 (53.3%)

Rh blood type, n (%)

0.733

Negative

61 (5.0%)

40 (4.8%)

21 (5.3%)

Positive

1,160

785 (95.2%)

375 (94.7%)

**Table 2.** Risk Factors and Outcomes (Mortality and Summative Length of Acute/Skilled Care Stay) Analysis With Respect to ABO/Rh Blood Groups
Risk factors	Total	ABO blood type	Rh type
*Denotes statistical significance. SD: standard deviation.
Age (n = 825), mean ± SD	57.64 ± 18.17	60.29 ± 18.74	61.52 ± 17.25	62.47 ± 16.84	55.01 ± 17.85	0.0001*	64.15 ± 17.97	57.31 ± 18.13	0.013*
Sex (n = 825)						0.344			0.36
Female	325	84	15	46	179		13	312
Male	500	135	12	66	287		27	473
Past medical history
Hypertension (n = 360), n (%)	289 (80%)	74 (21%)	12 (3%)	48 (13%)	155 (43%)	0.011*	13 (4%)	276 (77%)	0.069
Diabetes (n = 822), n (%)	317 (39%)	87 (11%)	15 (2%)	51 (6%)	164 (20%)	0.048*	11 (1%)	306 (37%)	0.14
BMI (n = 825), mean ± SD	28.35 ± 6.03	27.81 ± 5.63	27.57 ± 5.86	27.55 ± 6.68	28.83 ± 6.03	0.027*	29.32 ± 8.44	28.31 ± 5.88	0.867
HbA1c (n = 554), mean ± SD	6.92 ± 2.19	7.23 ± 2.42	6.32 ± 1.11	7.08 ± 1.94	6.78 ± 2.18	0.007*	6.32 ± 1.39	6.95 ± 2.22	0.205
Outcomes	A-positive	A-negative	B-positive	B-negative	AB-positive	AB-negative	O-positive	O-negative	P value
Total	17	203	1	26	5	107	17	449
Length of stay (days)									0.933
Mean	11.9	14.4	10	12.3	10.0	12.8	8.7	14.1
SD	10.28	16.66	-	13.7	4.85	13.93	7.91	14.9
Mortality, n (%)	6 (35%)	73 (36%)	1 (100%)	9 (35%)	4 (80%)	40 (37%)	10 (59%)	135 (30%)	0.032
Sub-groups by ABO/Rh factor		ABO blood type	Rh type
		A	AB	B	O	P value	Negative	Positive	P value
Mortality by ABO and Rh factor separately	Total	220	27	112	466	0.312	40	785	0.010*
	N (%)	79 (36%)	10 (37%)	44 (39%)	145 (31%)		21 (53%)	257 (33%)

Table 2. Risk Factors and Outcomes (Mortality and Summative Length of Acute/Skilled Care Stay) Analysis With Respect to ABO/Rh Blood Groups

Risk factors

Total

ABO blood type

Rh type

P value

Negative

Positive

P value

*Denotes statistical significance. SD: standard deviation.

Age (n = 825), mean ± SD

57.64 ± 18.17

60.29 ± 18.74

61.52 ± 17.25

62.47 ± 16.84

55.01 ± 17.85

0.0001*

64.15 ± 17.97

57.31 ± 18.13

0.013*

Sex (n = 825)

0.344

0.36

Female

325

179

312

Male

500

135

287

473

Past medical history

Hypertension (n = 360), n (%)

289 (80%)

74 (21%)

12 (3%)

48 (13%)

155 (43%)

0.011*

13 (4%)

276 (77%)

0.069

Diabetes (n = 822), n (%)

317 (39%)

87 (11%)

15 (2%)

51 (6%)

164 (20%)

0.048*

11 (1%)

306 (37%)

0.14

BMI (n = 825), mean ± SD

28.35 ± 6.03

27.81 ± 5.63

27.57 ± 5.86

27.55 ± 6.68

28.83 ± 6.03

0.027*

29.32 ± 8.44

28.31 ± 5.88

0.867

HbA1c (n = 554), mean ± SD

6.92 ± 2.19

7.23 ± 2.42

6.32 ± 1.11

7.08 ± 1.94

6.78 ± 2.18

0.007*

6.32 ± 1.39

6.95 ± 2.22

0.205

Outcomes

A-positive

A-negative

B-positive

B-negative

AB-positive

AB-negative

O-positive

O-negative

P value

Total

203

107

449

Length of stay (days)

0.933

Mean

11.9

14.4

12.3

10.0

12.8

8.7

14.1

10.28

16.66

13.7

4.85

13.93

7.91

14.9

Mortality, n (%)

6 (35%)

73 (36%)

1 (100%)

9 (35%)

4 (80%)

40 (37%)

10 (59%)

135 (30%)

0.032

Sub-groups by ABO/Rh factor

ABO blood type

Rh type

P value

Negative

Positive

P value

Mortality by ABO and Rh factor separately

Total

220

112

466

0.312

785

0.010*

N (%)

79 (36%)

10 (37%)

44 (39%)

145 (31%)

21 (53%)

257 (33%)

**Table 3.** Logistic Regression Analysis of ABO/Rh Blood Groups and Mortality for COVID-19 Patients
Rh antigen	Positive	Negative
*Denotes statistical significance.
A	1	-	1	0.97	0.34 - 2.73	0.96
B	1.06	0.65 - 1.73	0.81	7.12	0.78 - 64.93	0.08
O	0.77	0.54 - 1.09	0.135	2.54	0.93 - 6.97	0.07
AB	0.94	0.40 - 2.22	0.89	1	-	-

Table 3. Logistic Regression Analysis of ABO/Rh Blood Groups and Mortality for COVID-19 Patients

Rh antigen

Positive

Negative

Odds

95% Confidence interval

P value

95% Confidence interval

P value

*Denotes statistical significance.

0.97

0.34 - 2.73

0.96

1.06

0.65 - 1.73

0.81

7.12

0.78 - 64.93

0.08

0.77

0.54 - 1.09

0.135

2.54

0.93 - 6.97

0.07

0.94

0.40 - 2.22

0.89

**Table 4.** Logistic Regression Analysis Between the COVID-19 and Control Populations and Within the COVID-19 Population, Taking Into Account ABO/Rh Factor and Potential Confounding Variable on the Odds of Distribution of Infection With Respect to Potential Confounders (Sex, Age); as Well as Mortality (Sex, Age, BMI, HbA1c) Within the COVID-19 Population
	COVID-19 infection	Mortality (deceased on discharge)
*Denotes statistical significance. COVID-19: Coronavirus disease 2019; BMI: body mass index; HbA1c: hemoglobin A1c.
ABO factor
A	1				1.00
AB	0.476	0.256	0.883	0.019*	0.614	0.173	2.181	0.45
B	0.582	0.394	0.860	0.007*	0.942	0.504	1.762	0.852
O	0.882	0.652	1.194	0.417	1.068	0.672	1.697	0.779
Rhesus factor
Negative	1
Positive	1.182	0.680	2.055	0.59	0.448	0.185	1.067	0.070
Sex
Female	1
Male	1.850	1.446	2.367	< 0.001*	1.64	1.07	2.49	0.022*
Age	1.008	1.002	1.015	0.014*	1.05	1.037	1.067	< 0.001*
BMI					1.05	1.021	1.088	0.001*
HbA1c					1.16	1.061	1.261	0.001*

Table 4. Logistic Regression Analysis Between the COVID-19 and Control Populations and Within the COVID-19 Population, Taking Into Account ABO/Rh Factor and Potential Confounding Variable on the Odds of Distribution of Infection With Respect to Potential Confounders (Sex, Age); as Well as Mortality (Sex, Age, BMI, HbA1c) Within the COVID-19 Population

COVID-19 infection

Mortality (deceased on discharge)

Odds

95% Confidence interval

P value

Odds

95% Confidence interval

P value

*Denotes statistical significance. COVID-19: Coronavirus disease 2019; BMI: body mass index; HbA1c: hemoglobin A1c.

ABO factor

1.00

0.476

0.256

0.883

0.019*

0.614

0.173

2.181

0.45

0.582

0.394

0.860

0.007*

0.942

0.504

1.762

0.852

0.882

0.652

1.194

0.417

1.068

0.672

1.697

0.779

Rhesus factor

Negative

Positive

1.182

0.680

2.055

0.59

0.448

0.185

1.067

0.070

Sex

Female

Male

1.850

1.446

2.367

< 0.001*

1.64

1.07

2.49

0.022*

Age

1.008

1.002

1.015

0.014*

1.05

1.037

1.067

< 0.001*

BMI

1.05

1.021

1.088

0.001*

HbA1c

1.16

1.061

1.261

0.001*