Table 4.
Relative Risk of Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Healthcare Worker Contacts by Select Factorsa
| Factor | no./No. (%) | Univariate Model | Multivariate Model | ||
|---|---|---|---|---|---|
| RR (95% CI) | P Value | RR (95% CI) | P Value | ||
| Daily county incidence per resident (log10) | 0.89 (.33–2.39) | .812 | 0.84 (.28–2.49) | .749 | |
| Randomization arm | |||||
| Ascorbic acid | 4/59 (6.8) | ref | |||
| Hydroxychloroquine | 8/63 (12.7) | 1.87 (.51–6.83) | .342 | Not included | |
| Age (in decades) | 1.19 (.67–2.11) | .562 | Not included | ||
| Sex recorded at birth | |||||
| Female | 9/85 (10.6) | ref | |||
| Male | 3/37 (8.1) | 0.77 (.24–2.44) | .652 | Not included | |
| Race/ethnicity | |||||
| White (non-Hispanic) | 7/82 (8.5) | ref | |||
| Hispanic | 2/12 (16.7) | 1.95 (.46–8.30) | .365 | ||
| Asian | 3/15 (20.0) | 2.34 (.61–8.96) | .214 | ||
| Black or African American | 0/8 (0) | 0.00 (.00–.00) | <.0001∗∗∗ | ||
| Other | 0/5 (0) | 0.00 (.00–.00) | <.0001∗∗∗ | Not included | |
| Highest level of education | |||||
| High school graduate or GED | 2/4 (50.0) | ref | |||
| More than high school | 10/118 (8.5) | 0.17 (.04–.65) | .010∗ | Not included | |
| Contact smokes | |||||
| No | 10/112 (8.9) | ref | |||
| Yes | 2/10 (20.0) | 2.24 (.56–9.01) | .256 | Not included | |
| No. of suspected index cases | |||||
| 1 | 1/41 (2.4) | ref | ref | ||
| 2 | 4/14 (28.6) | 11.71 (1.41–97.02) | .023∗ | 8.18 (1.26–53.32) | .028∗ |
| >2 | 7/67 (10.4) | 4.28 (.55–33.57) | .166 | 1.92 (.34–11.03) | .463 |
| Hours of exposure to index case | |||||
| ≤2 | 1/57 (1.8) | ref | ref | ||
| 3–12 | 5/34 (14.7) | 8.38 (1.02–68.81) | .048∗ | 7.82 (1.09–56.21) | .041∗ |
| >12 | 6/31 (19.4) | 11.03 (1.34–90.55) | .025∗ | 11.81 (2.00–69.70) | .006∗∗ |
| Housing type | |||||
| House/condo/townhouse | 10/94 (10.6) | ref | |||
| Apartment | 1/22 (4.5) | 0.43 (.06–3.20) | .408 | ||
| Dormitory/fraternity/sorority | 1/1 (100.0) | 9.40 (5.03–17.57) | <.0001∗∗∗ | ||
| Other | 0/5 (0) | 0.00 (.00–.00) | <.0001∗∗∗ | Not included | |
| Bedrooms in household | |||||
| 0–1 | 1/16 (6.2) | ref | |||
| 2 | 1/26 (3.8) | 0.62 (.04–9.17) | .725 | ||
| 3 | 5/45 (11.1) | 1.78 (.22–14.10) | .586 | ||
| >3 | 5/34 (14.7) | 2.35 (.29–19.18) | .424 | Not included | |
| Bathrooms in household | |||||
| 1 | 2/36 (5.6) | ref | |||
| 2 | 4/43 (9.3) | 1.67 (.32–8.63) | .538 | ||
| >2 | 6/42 (14.3) | 2.57 (.53–12.37) | .239 | Not included | |
Abbreviations: CI, confidence interval; GED, General Educational Development; RR, relative risk.
Only variables with a P < .01, a size of at least 5 per group, and at least 1 infected contact per group were included in the multivariate model.
∗P < .05, ∗∗P < .01, ∗∗∗P < .001.