Table 2.
Crude and adjusted odds of SARS-CoV-2 IgG-positive status among health care workers at a large Midwestern health care system (N = 16 233), by demographic characteristics, Illinois and Wisconsin, June 8–July 10, 2020
| Characteristic | Overall | Illinois | Wisconsin | |||
|---|---|---|---|---|---|---|
| OR (95% CI) [P value] a | aOR (95% CI) [P value] a | OR (95% CI) [P value] a | aOR (95% CI) [P value] a | OR (95% CI) [P value] a | aOR (95 CI%) [P value] a | |
| Age, y | ||||||
| 18-31 | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] |
| 32-40 | 0.54 (0.43-0.67) [<.001] | 0.54 (0.43-0.68) [<.001] | 0.54 (0.41-0.72) [<.001] | 0.52 (0.39-0.71) [<.001] | 0.54 (0.32-0.78) [.001] | 0.56 (0.38-0.81) [.002] |
| 41-52 | 0.63 (0.51-0.78) [<.001] | 0.66 (0.53-0.83) [<.001] | 0.61 (0.46-0.80) [<.001] | 0.62 (0.47-0.83) [.001] | 0.68 (0.48-0.95) [.03] | 0.70 (0.49-1.00) [.047] |
| 53-82 | 0.55 (0.44-0.69) [<.001] | 0.65 (0.51-0.83) [<.001] | 0.48 (0.36-0.64) [<.001] | 0.53 (0.39-0.73) [<.001] | 0.62 (0.43-0.89) [.01] | 0.71 (0.48-1.04) [.08] |
| Race | ||||||
| White | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] |
| Black | 3.65 (2.76-4.83) [<.001] | 3.86 (2.91-5.12) [<.001] | 2.34 (1.63-3.36) [<.001] | 2.54 (1.76-3.66) [<.001] | 4.58 (2.91-7.19) [<.001] | 4.79 (3.04-7.55) [<.001] |
| Asian | 1.12 (1.40-2.63) [<.001] | 1.87 (1.37-2.57) [<.001] | 1.42 (1.01-2.01) [.046] | 1.39 (0.98-1.98) [.06] | 0.97 (0.40-2.39) [.95] | 0.97 (0.40-2.39) [.95] |
| American Indian | 1.15 (0.28-4.71) [.85] | 0.85 (0.20-3.55) [.82] | 1.15 (0.27-4.85) [.84] | 0.93 (0.22-4.04) [.92] | — b | — b |
| Mixed | 2.18 (1.65-2.88) [<.001] | 1.99 (1.50-2.63) [<.001] | 1.34 (0.99-1.81) [.05] | 1.27 (0.94-1.72) [.12] | 1.20 (0.38-3.80) [.76] | 1.11 (0.32-3.26) [.97] |
| Ethnicity | ||||||
| Non-Hispanic | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] |
| Hispanic | 1.94 (1.49-2.52) [<.001] | 1.80 (1.34-2.42) [<.001] | 1.49 (1.08-2.05) [.01] | 1.44 (0.99-2.10) [.06] | 2.06 (1.27-3.33) [.003] | 2.12 (1.30-3.45) [.003] |
| Clinical role c | ||||||
| Nonclinical | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] | 1.0 [Ref] |
| Clinical | 1.17 (0.96-1.44) [.12] | 1.09 (0.88-1.35) [.41] | 1.18 (0.91-1.54) [.21] | 1.09 (0.82-1.44) [.57] | 1.21 (0.88-1.66) [.25] | 1.13 (0.82-1.57) [.46] |
| COVID-19–clinical | 2.22 (1.76-2.81) [<.001] | 1.86 (1.45-2.40) [<.001] | 2.10 (1.57-2.81) [<.001] | 1.76 (1.28-2.42) [.001] | 1.69 (1.11-2.58) [.02] | 1.47 (0.94-2.29) [.09] |
Abbreviations: aOR, adjusted odds ratio; COVID-19, coronavirus disease 2019; IgG, immunoglobulin G; IQR, interquartile range; OR, odds ratio; ref, reference group; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
aSignificance was determined using the Wald χ2 test for direct differences between a variable level relative to the reference level of the same variable, with P < .05 considered significant.
bAt least one category count for this level of race was 0, inhibiting the calculating of ORs.
cClinical role was categorized as COVID-19–clinical (participants working in a clinical capacity on COVID-19–designated units), clinical (participants working in a clinical capacity on non–COVID-19–designated units), or nonclinical (participants in nonclinical roles such as administration and hospital support staff).