Table 3. Multivariable analysis of factors associated with SARS-CoV-2 infection.
| Adjusted for demographic, home and work factors during lockdown (n = 10,772) | Adjusted for demographic and home factors (n = 12,541) | |||
|---|---|---|---|---|
| Variable | aOR (95% CI) | P value | aOR (95% CI) | P value |
| Demographic and household factors | ||||
| Age* | 0.92 (0.88–0.97) | 0.001 | 0.85 (0.82–0.88) | <0.001 |
| Sex | ||||
| Male | Ref | - | Ref | - |
| Female | 1.03 (0.91–1.16) | 0.66 | 0.91 (0.82–1.00) | 0.06 |
| Ethnicity | ||||
| White | Ref | - | Ref | - |
| Asian | 0.87 (0.74–1.01) | 0.07 | 0.84 (0.73–0.95) | 0.007 |
| Black | 0.97 (0.76–1.24) | 0.82 | 0.93 (0.74–1.16) | 0.50 |
| Mixed | 0.83 (0.65–1.07) | 0.16 | 0.85 (0.68–1.05) | 0.14 |
| Other | 0.79 (0.55–1.11) | 0.18 | 0.82 (0.60–1.11) | 0.21 |
| Migration status | ||||
| Born in UK | Ref | - | Ref | - |
| Born abroad | 1.09 (0.96–1.24) | 0.17 | 1.09 (0.97–1.22) | 0.13 |
| Religiosity | ||||
| Not important or not religious | Ref | - | Ref | - |
| Fairly important | 1.08 (0.95–1.22) | 0.25 | 1.09 (0.97–1.21) | 0.16 |
| Very important | 1.05 (0.88–1.25) | 0.58 | 1.16 (1.00–1.35) | 0.06 |
| Extremely important | 1.28 (1.08–1.51) | 0.004 | 1.29 (1.11–1.50) | 0.001 |
| IMD | ||||
| 1 (most deprived) | 1.02 (0.85–1.23) | 0.82 | 1.16 (0.98–1.37) | 0.08 |
| 2 | 1.08 (0.92–1.26) | 0.36 | 1.11 (0.96–1.30) | 0.16 |
| 3 | Ref | - | Ref | - |
| 4 | 1.01 (0.88–1.17) | 0.84 | 0.99 (0.86–1.14) | 0.91 |
| 5 (least deprived) | 1.05 (0.91–1.21) | 0.47 | 1.02 (0.89–1.16) | 0.82 |
| Household size | 1.02 (0.98–1.06) | 0.34 | 1.01 (0.97–1.04) | 0.67 |
| Cohabitation | ||||
| Does not live with other key workers | Ref | - | Ref | - |
| Lives with other key workers | 1.17 (1.06–1.30) | 0.002 | 1.27 (1.16–1.39) | <0.001 |
| Accommodation | ||||
| Does not have shared spaces | Ref | - | Ref | - |
| Has shared spaces | 0.93 (0.81–1.06) | 0.28 | 1.00 (0.89–1.13) | 0.95 |
| Social mixing with others outside household | ||||
| None/remote only | Ref | - | Ref | - |
| Face to face with social distancing | 0.91 (0.81–1.01) | 0.09 | 0.90 (0.81–1.00) | 0.05 |
| With physical contact | 0.98 (0.84–1.15) | 0.85 | 1.04 (0.90–1.21) | 0.56 |
| Comorbidities | ||||
| Diabetes | 1.11 (0.86–1.44) | 0.41 | 1.12 (0.89–1.40) | 0.32 |
| Immunosuppression | 1.00 (0.73–1.36) | 0.99 | 0.93 (0.70–1.23) | 0.60 |
| Shielding status | ||||
| Not advised to shield | Ref | - | Ref | - |
| Advised to shield | 0.89 (0.66–1.18) | 0.41 | 0.81 (0.63–1.04) | 0.11 |
| Smoking status | ||||
| Ex- or nonsmoker | Ref | - | Ref | - |
| Current smoker | 0.56 (0.44–0.72) | <0.001 | 0.63 (0.50–0.79) | <0.001 |
| COVID-19 vaccination status (at time of questionnaire response) | ||||
| Unvaccinated | Ref | - | Ref | - |
| Vaccinated | 0.62 (0.54–0.72) | <0.001 | 0.84 (0.75–0.94) | 0.003 |
| Region of workplace | ||||
| West Midlands | Ref | - | Ref | - |
| London | 1.11 (0.90–1.38) | 0.33 | 1.13 (0.94–1.36) | 0.20 |
| South East England | 0.84 (0.68–1.05) | 0.12 | 0.88 (0.72–1.07) | 0.19 |
| South West England or Channel Islands | 0.58 (0.45–0.74) | <0.001 | 0.61 (0.49–0.77) | <0.001 |
| East of England | 0.76 (0.59–0.96) | 0.02 | 0.80 (0.64–0.99) | 0.04 |
| East Midlands | 0.88 (0.70–1.10) | 0.25 | 0.87 (0.71–1.07) | 0.18 |
| North East England | 0.87 (0.65–1.15) | 0.32 | 0.94 (0.73–1.22) | 0.65 |
| North West England or Isle of Man | 1.21 (0.98–1.49) | 0.08 | 1.25 (1.02–1.53) | 0.04 |
| Yorkshire and the Humber | 1.13 (0.89–1.43) | 0.33 | 1.10 (0.88–1.36) | 0.41 |
| Wales | 1.11 (0.82–1.50) | 0.51 | 1.13 (0.82–1.47) | 0.54 |
| Scotland | 0.44 (0.32–0.59) | <0.001 | 0.49 (0.38–0.63) | <0.001 |
| Northern Ireland | 0.47 (0.27–0.80) | 0.006 | 0.50 (0.30–0.81) | 0.005 |
| Time between questionnaire rollout and questionnaire completion (per day) | 1.00 (1.00–1.01) | 0.001 | 1.00 (1.00–1.00) | 0.87 |
| Occupational factors | ||||
| Occupation | ||||
| Doctor or medical support | Ref | - | - | - |
| Nurse, nursing associate, or Midwife | 1.30 (1.11–1.53) | 0.001 | - | - |
| Allied health professional† | 1.01 (0.87–1.16) | 0.94 | - | - |
| Dental | 0.70 (0.51–0.96) | 0.03 | - | - |
| Admin, estates, or other | 1.18 (0.91–1.53) | 0.21 | - | - |
| Transport to work | ||||
| Alone or with members of household | Ref | - | - | - |
| With others outside household | 1.10 (0.93–1.29) | 0.27 | - | - |
| Number of SARS-CoV-2–positive patients attended to per week (with physical contact) | ||||
| None | Ref | - | - | - |
| 1–5 | 1.70 (1.49–1.95) | <0.001 | - | - |
| 6–20 | 2.13 (1.82–2.50) | <0.001 | - | - |
| ≥21 | 2.59 (2.11–3.18) | <0.001 | - | - |
| Access to appropriate PPE | ||||
| Not applicable or all/most of the time | Ref | - | - | - |
| Some of the time or less frequently | 1.29 (1.17–1.43) | <0.001 | - | - |
| AGP exposure | ||||
| Less than weekly exposure | Ref | - | - | - |
| At least weekly exposure | 0.91 (0.80–1.04) | 0.17 | - | - |
| Night shift pattern | ||||
| Never works nights | Ref | - | - | - |
| Works nights less than weekly | 1.10 (0.96–1.27) | 0.17 | - | - |
| Works nights weekly or always | 0.85 (0.72–1.00) | 0.05 | - | - |
| Work areas | ||||
| Ambulance | 2.00 (1.56–2.58) | <0.001 | - | - |
| Community clinical setting/primary care | 0.93 (0.81–1.06) | 0.27 | - | - |
| Nonclinical community setting | 0.91 (0.72–1.15) | 0.45 | - | - |
| Emergency department | 1.10 (0.94–1.30) | 0.25 | - | - |
| Intensive care unit | 0.76 (0.64–0.92) | 0.003 | - | - |
| Hospital inpatient | 1.55 (1.38–1.75) | <0.001 | - | - |
| Hospital outpatient | 0.94 (0.82–1.07) | 0.36 | - | - |
| Hospital nonclinical area or laboratory | 0.87 (0.73–1.03) | 0.11 | - | - |
| Psychiatric hospital | 1.31 (1.00–1.71) | 0.05 | - | - |
| Maternity | 0.67 (0.50–0.89) | 0.006 | - | - |
| Nursing or care home | 1.34 (0.99–1.81) | 0.06 | - | - |
| University | 0.90 (0.63–1.29) | 0.57 | - | - |
| Home | 0.79 (0.68–0.92) | 0.002 | - | - |
Table 3 shows the results of 2 multivariable logistic regression analyses, 1 containing the whole analysed cohort, examining the association of demographic and household factors with infection, and the other containing the cohort working during lockdown, additionally adjusted for occupational factors.
*For each decade increase in age.
†Also includes pharmacists, healthcare scientists, ambulance workers, and those in optical roles.
Analyses adjusted for all other variables in the table (with the exception of the exclusion of occupational risk factors in the right-hand columns—as indicated by the lack of results in the relevant sections).
All occupational factors (other than region of workplace) relate to work circumstances during the weeks following the first UK national lockdown on March 23, 2020. When asked about work areas participants could select multiple answers, therefore the work areas variables are “dummy” variables comparing all those that did not select an area (reference) with all those that did. Region of workplace is included in the analysis of household and demographic factors as a proxy for the participants region of residence.
AGP, aerosol generating procedure; aOR, adjusted odds ratio; CI, confidence interval; COVID-19, Coronavirus Disease 2019; IMD, index of multiple deprivation; PPE, personal protective equipment; Ref, reference category for categorical variables; SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus 2.