Table 1.

Characteristics of 222,670 Individuals in Ontario, Canada, With Known ABO Blood Group, and Who Subsequently Underwent SARS-CoV-2 Viral RNA PCR Testing Between January 15, 2020, and June 30, 2020.

Characteristic		O blood group (N = 98,664)	Non-O blood groups* (N = 124,006)	Standardized difference
At the ABO specimen date (first time zero)
Mean (SD) age, y		50.7 (21.3)	50.7 (21.3)	.00
At the SARS-CoV-2 specimen date (second time zero)
Mean (SD) age, y		54.4 (20.8)	54.2 (20.7)	.01
Female		70,485 (71.4)	87,986 (71.0)	.01
Income quintile (Q)	Q1 (lowest)	21,113 (21.4)	25,558 (20.6)	.02
	Q2	19,063 (19.3)	23,703 (19.1)	.01
	Q3	17,836 (18.1)	22,649 (18.3)	.00
	Q4	17,131 (17.4)	21,487 (17.3)	.00
	Q5 (highest)	15,738 (16.0)	20,169 (16.3)	.01
Within 5 years before the SARS-CoV-2 specimen collection date
Pulmonary embolism or deep vein thrombosis		3,793 (3.8)	5,543 (4.5)	.03
Malignancy		28,230 (28.6)	35,481 (28.6)	.00
Cardiac ischemia/arrhythmia		14,382 (14.6)	18,292 (14.8)	.00
Chronic kidney disease		11,446 (11.6)	14,088 (11.4)	.01
Stroke or transient ischemic attack		4,013 (4.1)	4,966 (4.0)	.00
Anemia		21,489 (21.8)	26,856 (21.7)	.00
Any time before the SARS-CoV-2 specimen collection date
Congestive heart failure		10,834 (11.0)	13,859 (11.2)	.01
Diabetes mellitus		21,057 (21.3)	27,147 (21.9)	.01
Chronic hypertension		41,109 (41.7)	50,612 (40.8)	.02
Asthma		20,020 (20.3)	24,855 (20.0)	.01
COPD		15,885 (16.1)	19,642 (15.9)	.01
Dementia or frailty		37,176 (37.7)	45,891 (37.0)	.01
HIV or organ transplant		914 (0.9)	1,188 (1.0)	.00
Median (IQR) duration of follow-up from the ABO specimen date, y		3.1 (1.6-5.4)	3.1 (1.6-5.4)	.00
Median (IQR) duration of follow-up from the SARS-CoV-2 specimen date, y		0.2 (0.1-0.3)	0.2 (0.1-0.3)	.00

All data are presented as a number (%) unless otherwise indicated.

*Non-O blood groups are A, AB and B.