Table 1 Characteristics of the study population included in the main analysis, stratified by vaccination status

From: Post-COVID conditions following COVID-19 vaccination: a retrospective matched cohort study of patients with SARS-CoV-2 infection

 

Unvaccinated (N = 161,531)

Vaccinated (N = 161,531)

Total (N = 323,062)

P-value*

ASMD

Age at index date, years

   

1

0.00

< 12

11062 (6.8%)

11062 (6.8%)

22124 (6.8%)

  

12–17

16478 (10.2%)

16478 (10.2%)

32956 (10.2%)

  

18–24

16284 (10.1%)

16284 (10.1%)

32568 (10.1%)

  

25–39

48567 (30.1%)

48567 (30.1%)

97134 (30.1%)

  

40–49

28298 (17.5%)

28298 (17.5%)

56596 (17.5%)

  

50–64

29299 (18.1%)

29299 (18.1%)

58598 (18.1%)

  

65–74

7950 (4.9%)

7950 (4.9%)

15900 (4.9%)

  

75+

3593 (2.2%)

3593 (2.2%)

7186 (2.2%)

  

Mean (SD)

37.1 (17.9)

37.1 (17.9)

37.1 (17.9)

1

0.00

Median [Q1, Q3]

36.0 [23.0, 50.0]

36.0 [23.0,50.0]

36.0 [23.0, 50.0]

  

Sex

   

1

0.00

Female

88067 (54.5%)

88067 (54.5%)

176134 (54.5%)

  

Male

73464 (45.5%)

73464 (45.5%)

146928 (45.5%)

  

Race and ethnicity

   

< 0.001

0.32

Hispanic

58507 (36.2%)

58477 (36.2%)

116984 (36.2%)

  

Asian

6536 (4.0%)

19583 (12.1%)

26119 (8.1%)

  

Black

16219 (10.0%)

10651 (6.6%)

26870 (8.3%)

  

White

63899 (39.6%)

56079 (34.7%)

119978 (37.1%)

  

Multiple/Other/Unknown

16370 (10.1%)

16741 (10.4%)

33111 (10.2%)

  

Participating VSD site

   

1

0.00

A

44319 (27.4%)

44319 (27.4%)

88638 (27.4%)

  

B

6462 (4.0%)

6462 (4.0%)

12924 (4.0%)

  

C

4365 (2.7%)

4365 (2.7%)

8730 (2.7%)

  

D

4111 (2.5%)

4111 (2.5%)

8222 (2.5%)

  

E

9552 (5.9%)

9552 (5.9%)

19104 (5.9%)

  

F

1016 (0.6%)

1016 (0.6%)

2032 (0.6%)

  

G

88483 (54.8%)

88483 (54.8%)

176966 (54.8%)

  

H

3223 (2.0%)

3223 (2.0%)

6446 (2.0%)

  

SARS-CoV-2 variant period

   

0.783

0.00

Alpha (Mar–Jun 2021)

2856 (1.8%)

2804 (1.7%)

5660 (1.8%)

  

Delta (Jul–Nov 2021)

50578 (31.3%)

50578 (31.3%)

101156 (31.3%)

  

Omicron (Dec 2021–Feb 2022)

108097 (66.9%)

108149 (67.0%)

216246 (66.9%)

  

Medicaid subsidized insurance

26340 (16.3%)

17737 (11.0%)

44077 (13.6%)

< 0.001

0.16

COVID-19 vaccine doses received**

   

N/A

N/A

1

0 (-)

5379 (3.3%)

N/A

  

2

0 (-)

127687 (79.0%)

N/A

  

3+

0 (-)

28465 (17.6%)

N/A

  

Time since most recent vaccine dose

   

N/A

N/A

< 90 days

0 (-)

50408 (31.2%)

N/A

  

90–180 days

0 (-)

47957 (29.7%)

N/A

  

> 180 days

0 (-)

63166 (39.1%)

N/A

  

Received influenza vaccine in prior 2 years

48645 (30.1%)

107775 (66.7%)

156420 (48.4%)

< 0.001

0.79

Prior positive SARS-CoV-2 test

16651 (10.3%)

11068 (6.9%)

27719 (8.6%)

< 0.001

0.12

Number of outpatient encounters in prior year

  

< 0.001

0.32

0

21529 (13.3%)

9996 (6.2%)

31525 (9.8%)

  

1 – 3

52719 (32.6%)

42025 (26.0%)

94744 (29.3%)

  

4 – 6

29484 (18.3%)

35297 (21.9%)

64781 (20.1%)

  

7+

57799 (35.8%)

74213 (45.9%)

132012 (40.9%)

  

Weighted Charlson Comorbidity Score

   

< 0.001

0.09

0

130848 (81.0%)

126015 (78.0%)

256863 (79.5%)

  

1–2

24058 (14.9%)

26396 (16.3%)

50454 (15.6%)

  

3 +

6625 (4.1%)

9120 (5.6%)

15745 (4.9%)

  

Follow-up days

   

< 0.001

0.44

Mean (SD)

135.9 (38.4)

116.7 (49.0)

126.3 (45.1)

  

Median [Q1, Q3]

151.0 [151.0, 152.0]

151.0 [81.0, 151.0]

151.0 [117.0, 151.0]

  
  1. ASMD Absolute standardized mean difference, N/A Not applicable. *Differences across categories of population characteristics were compared between vaccinated and unvaccinated cases using χ2 test for categorical variables and Wilcoxon rank sum test for continuous variables. **COVID-19 vaccine count defined as number of documented mRNA COVID-19 vaccines (Pfizer-BioNTech or Moderna) or Janssen (Johnson & Johnson) COVID-19 vaccines received ≥ 14 days prior to index.
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