Survey with serology results (N=955) | |||||||
Seropositive (N=779) | Seronegative (N=176) | Bivariate‡‡ PR (95% CI), p value | Multivariable‡‡ PR (95% CI), p value | ||||
Characteristic | Category | n | % | n | % | ||
Age (years) | 20–29 | 101 | 73.7 | 36 | 26.3 | 1.00 (REFERENCE) | 1.00 (REFERENCE) |
30–39 | 175 | 82.6 | 37 | 17.5 | 0.66 (0.43 to 0.99), p=0.045 | 0.69 (0.45 to 1.04), p=0.08 | |
40–49 | 159 | 82.4 | 34 | 17.6 | 0.68 (0.45 to 1.04), p=0.07 | 0.74 (0.49 to 1.11), p=0.14 | |
50–59 | 209 | 82.3 | 45 | 17.7 | 0.65 (0.44 to 0.97), p=0.03 | 0.77 (0.52 to 1.14), p=0.18 | |
60–69 | 124 | 85.0 | 22 | 15.1 | 0.57 (0.36 to 0.92), p=0.02* | 0.60 (0.37 to 0.97), p=0.04* | |
70+ | 11 | 84.6 | 2 | 15.4 | |||
Gender† | Female | 620 | 82.1 | 135 | 17.9 | 1.00 (REFERENCE) | 1.00 (REFERENCE) |
Male | 154 | 79.4 | 40 | 20.6 | 1.15 (0.84 to 1.59), p=0.39 | 1.18 (0.85 to 1.63), p=0.32 | |
Race/ethnicity† | White | 413 | 81.0 | 97 | 19.0 | 1.00 (REFERENCE) | 1.00 (REFERENCE) |
Black | 91 | 81.3 | 21 | 18.8 | 0.98 (0.64 to 1.50), p=0.92 | 1.06 (0.69 to 1.63), p=0.78 | |
Hispanic | 125 | 83.9 | 24 | 16.1 | 0.84 (0.56 to 1.27), p=0.40 | 0.86 (0.57 to 1.29), p=0.47 | |
Asian/Pacific Islander | 123 | 80.4 | 30 | 19.6 | 0.95 (0.65 to 1.39), p=0.80* | 0.97 (0.65 to 1.44), p=0.87* | |
American Indian | 3 | 100.0 | 0 | 0 | |||
Two or more races | 5 | 83.3 | 1 | 16.7 | |||
Non-specified/missing | 19 | 86.4 | 3 | 13.6 | |||
Work contract | Full-time day | 521 | 82.8 | 108 | 17.2 | 1.00 (REFERENCE)* | |
Full-time other | 110 | 76.4 | 34 | 23.6 | |||
Part-time day | 95 | 76.6 | 29 | 23.4 | 1.06 (0.74 to 1.51), p=0.75* | ||
Part-time other | 35 | 94.6 | 2 | 5.4 | |||
Missing | 18 | 85.7 | 3 | 14.3 | |||
Work location | ICU | 35 | 71.4 | 14 | 28.6 | 1.00 (REFERENCE) | 1.00 (REFERENCE) |
ED | 72 | 82.76 | 15 | 17.2 | 0.62 (0.33 to 1.17), p=0.14 | 0.61 (0.33 to 1.13), p=0.12 | |
Hospital units (non-ICU) | 209 | 80.4 | 51 | 19.6 | 0.69 (0.41 to 1.15), p=0.15 | 0.7 (0.43 to 1.14), p=0.15 | |
Other | 456 | 82.9 | 94 | 17.1 | 0.60 (0.37 to 0.97), p=0.04 | 0.58 (0.36 to 0.93), p=0.02 | |
Missing | 7 | 77.8 | 2 | 22.2 | |||
Work county‡ | Nassau | 176 | 80.0 | 44 | 20.0 | 1.00 (REFERENCE) | |
Manhattan | 84 | 78.5 | 23 | 21.5 | 1.09 (0.69 to 1.70), p=0.72 | ||
Queens | 93 | 82.3 | 20 | 17.7 | 0.88 (0.55 to 1.43), p=0.62 | ||
Richmond | 88 | 82.2 | 19 | 17.8 | 0.86 (0.52 to 1.41), p=0.54 | ||
Suffolk | 85 | 83.3 | 17 | 16.7 | 0.85 (0.50 to 1.46), p=0.56 | ||
Westchester | 26 | 74.3 | 9 | 25.7 | 1.31 (0.70 to 2.44), p=0.39 | ||
Other/unknown | 227 | 83.8 | 44 | 16.2 | 0.78 (0.52 to 1.14), p=0.21 | ||
Residential county‡ | Nassau | 219 | 79.6 | 56 | 20.4 | 1.00 (REFERENCE) | |
Bronx | 21 | 80.8 | 5 | 19.2 | 0.98 (0.43 to 2.22), p=0.95 | ||
Kings | 36 | 81.8 | 8 | 18.2 | 0.92 (0.47 to 1.81), p=0.81 | ||
New York | 26 | 74.3 | 9 | 25.7 | 1.23 (0.64 to 2.36), p=0.53 | ||
Queens | 141 | 82.9 | 29 | 17.1 | 0.87 (0.58 to 1.31), p=0.51 | ||
Richmond | 86 | 86.9 | 13 | 13.1 | 0.68 (0.39 to 1.19), p=0.18 | ||
Suffolk | 141 | 83.9 | 27 | 16.1 | 0.84 (0.55 to 1.28), p=0.42 | ||
Westchester | 50 | 79.4 | 13 | 20.6 | 1.06 (0.62 to 1.83), p=0.82 | ||
Other/unknown | 59 | 78.7 | 16 | 21.3 | 1.24 (0.73 to 2.11), p=0.42 | ||
New York City | 310 | 82.9 | 64 | 17.1 | 1.00 (REFERENCE) | 1.00 (REFERENCE) | |
Long Island | 360 | 81.3 | 83 | 18.7 | 1.08 (0.80 to 1.46), p=0.60 | 1.25 (0.92 to 1.7), p=0.15 | |
Other | 109 | 79.0 | 29 | 21.0 | 1.32 (0.88 to 1.99), p=0.18 | 1.5 (1 to 2.24), p=0.05 | |
PCR | Positive | 391 | 89.9 | 44 | 10.1 | 1.00 (REFERENCE) | 1.00 (REFERENCE) |
Negative | 61 | 75.3 | 20 | 24.7 | 2.45 (1.51 to 3.96), p=0.001 | 2.22 (1.38 to 3.59), p=0.001 | |
No PCR test | 327 | 74.7 | 111 | 25.3 | 2.50 (1.80 to 3.47), p<0.0001 | 2.56 (1.83 to 3.58), p<0.0001 | |
Equivocal | 0 | 0 | 1 | 100 | |||
Re-exposure§ | Low | 463 | 83.1 | 94 | 16.9 | 1.00 (REFERENCE) | |
Medium | 203 | 79.0 | 54 | 21.0 | 1.24 (0.91 to 1.68), p=0.17 | ||
High | 113 | 80.1 | 28 | 19.9 | 1.17 (0.80 to 1.73), p=0.42 | ||
Reinfected/ill¶ | No | 728 | 81.3 | 167.0 | 18.7 | 1.00 (REFERENCE) | |
Yes | 51 | 85.0 | 9.0 | 15.0 | 0.82 (0.44 to 1.52), p=0.52 | ||
Recent travel** | No | 718 | 81.4 | 164 | 18.6 | 1.00 (REFERENCE) | |
Yes | 60 | 83.3 | 12 | 16.7 | 0.94 (0.55 to 1.60), p=0.81 | ||
Missing | 1 | 100 | 0 | 0 | |||
Public transport†† | No | 681 | 81.6 | 154 | 18.4 | 1.00 (REFERENCE) | |
Yes | 94 | 81.7 | 21 | 18.3 | 0.99 (0.65 to 1.52), p=0.98 | ||
Missing | 4 | 80.0 | 1 | 20.0 | |||
Days between antibody testing | Mean=140 SD=10 Minimum=105 Maximum=174 | Mean=139 SD=12 Minimum=62 Maximum=158 | 0.99 (0.98 to 1.00), p=0.21 | 0.99 (0.98 to 1.01), p=0.37 |
*In regression models, the following categories were combined: Age=60+ years of age; race/ethnicity (Asian/Pacific Islander, American Indian, two or more races); shift=full time versus part-time.
†Administrative data collected from self-reports in prespecified fixed categories.
‡New York City=Bronx, Kings, New York, Queens, and Richmond; Long Island=Nassau and Suffolk; other=Westchester and other/unknown.
§‘Do you believe you may have been exposed again to COVID-19?’ (1–3=low; 4–6=medium; 7–9=high suspicion of re-exposure).
¶‘If so, did you feel ill?’ (Yes/No).
**‘In the past month, have you traveled outside of the NY metropolitan region and northeast?’ (Yes/No).
††‘Do you usually take public transportation to work?’ (Yes/No).
‡‡Clopper-Pearson 95% CIs. SAS GLIMMIX procedure modelling the probability of being seronegative (includes key sociodemographic and work characteristic variables), using a Newton-Raphson optimisation and type III test for fixed effects, missing values were excluded from the analyses; bolded prevalence ratios (PRs) indicate statistically significant associations at p<0.05. A PR greater than 1 is compared with the reference group; similarly, a PR less than 1.00 indicates that the group was less likely to seroconvert to negative.
ED, emergency department; ICU, intensive care unit; n, subsample count; N, sample count.