Table 3.
Risk factors for antibody positivity in staff participating in school surveillance during the summer half-term (June to mid-July, 2020)
|
Antibody positive |
Univariable analysis (n=1381) |
Complete case univariable analysis adjusted for clustering by school (n=1307) |
Multivariable analysis adjusted for clustering by school (p=0·0002; n=1307) |
|||||
|---|---|---|---|---|---|---|---|---|
| n/N (%) | OR (95% CI) | p value* | OR (95% CI) | p value* | OR (95% CI) | p value* | ||
| Sex | .. | .. | 0·066 | .. | 0·11 | .. | 0·20 | |
| Female | 158/1107 (14·3%) | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Male | 51/272 (18·8%) | 1·39 (0·98–1·96) | .. | 1·36 (0·94–1·96) | .. | 1·28 (0·88–1·87) | .. | |
| Missing | 0/2 | NA | NA | NA | NA | NA | NA | |
| Ethnicity | .. | .. | 0·0004 | .. | 0·0028 | .. | 0·018 | |
| White | 140/1048 (13·4%) | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Mixed or multiple ethnic groups | 13/49 (26·5%) | 2·34 (1·21–4·53) | .. | 2·32 (1·15–4·67) | .. | 1·99 (0·98–4·04) | .. | |
| Black or Black British | 22/71 (31·0%) | 2·91 (1·71–4·96) | .. | 2·78 (1·56–4·94) | .. | 2·49 (1·38–4·46) | .. | |
| Asian or Asian British | 26/163 (16·0%) | 1·23 (0·78–1·94) | .. | 1·22 (0·73–2·02) | .. | 1·16 (0·69–1·95) | .. | |
| Other ethnic group | 5/31 (16·1%) | 1·25 (0·47–3·30) | .. | 1·43 (0·51–4·02) | .. | 1·39 (0·49–3·93) | .. | |
| Missing | 3/19 (15·8%) | NA | NA | NA | NA | NA | NA | |
| Region | .. | .. | 0·0003 | .. | 0·051 | .. | 0·085 | |
| Derby | 8/133 (6·0%) | 0·27 (0·13–0·57) | .. | 0·26 (0·10–0·69) | .. | 0·27 (0·10–0·73) | .. | |
| East London | 84/489 (17·2%) | 0·87 (0·62–1·22) | .. | 0·81 (0·47–1·42) | .. | 0·70 (0·39–1·24) | .. | |
| Manchester | 29/257 (11·3%) | 0·53 (0·34–0·84) | .. | 0·55 (0·28–1·09) | .. | 0·55 (0·28–1·09) | .. | |
| North London | 83/431 (19·3%) | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Oxford | 5/71 (7·0%) | 0·32 (0·12–0·81) | .. | 0·40 (0·09–1·81) | .. | 0·48 (0·11–2·14) | .. | |
| Attended school during lockdown | .. | .. | 0·048 | .. | 0·21 | .. | 0·20 | |
| No | 41/203 (20·2%) | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Yes | 164/1116 (14·7%) | 0·68 (0·47–1·00) | .. | 0·77 (0·50–1·16) | .. | 0·73 (0·48–1·12) | .. | |
| Missing | 4/62 (6·5%) | NA | NA | NA | NA | NA | NA | |
| Frequency of school attendance during lockdown | .. | .. | 0·14 | .. | .. | .. | .. | |
| Only home | 41/203 (20·2%) | 1 (ref) | .. | .. | .. | .. | .. | |
| Mainly home | 66/502 (13·1%) | 0·60 (0·39–0·92) | .. | .. | .. | .. | .. | |
| Equal school and home | 53/318 (16·7%) | 0·79 (0·50–1·24) | .. | .. | .. | .. | .. | |
| Mainly school | 31/183 (16·9%) | 0·81 (0·48–1·35) | .. | .. | .. | .. | .. | |
| Full time | 14/113 (12·4%) | 0·56 (0·29–1·08) | .. | .. | .. | .. | .. | |
| Missing | 4/62 (6·5%) | NA | NA | .. | .. | .. | .. | |
| Student contact during lockdown | .. | .. | 0·37 | .. | .. | .. | .. | |
| None | 69/385 (17·9%) | 1 (ref) | .. | .. | .. | .. | .. | |
| Occasional | 105/698 (15·0%) | 0·81 (0·58–1·13) | .. | .. | .. | .. | .. | |
| Regular | 28/198 (14·1%) | 0·75 (0·47–1·22) | .. | .. | .. | .. | .. | |
| Missing | 7/100 (7·0%) | NA | NA | .. | .. | .. | .. | |
| Other household occupation | .. | .. | 0·0023 | .. | 0·0020 | .. | 0·0069 | |
| Not a health-care or key worker | 158/1135 (13·9%) | 1 (ref) | .. | 1 (ref) | .. | 1 (ref) | .. | |
| Health-care worker | 14/43 (32·6%) | 2·99 (1·54–5·77) | .. | 3·45 (1·69–7·03) | .. | 3·08 (1·48–6·41) | .. | |
| Key worker (excluding health-care workers) | 37/203 (18·2%) | 1·38 (0·93–2·04) | .. | 1·35 (0·88–2·06) | .. | 1·35 (0·88–2·07) | .. | |
NA=not applicable. OR=odds ratio.
*
Global p values calculated using Wald test.