Table 4.
ORs and 95% CIs for risk of testing positive on COVID-19 test
| Exposure | Category | Crude job type association (n=70 878) |
Base model* (n=70 878) |
Base model*+test reason (n=70 646) |
Final model† (n=70 646) |
| Job category | Energy operations | 0.98 (0.86 to 1.12) | 1.22 (0.99 to 1.51) | 0.91 (0.70 to 1.19) | 0.91 (0.70 to 1.20) |
| Engineering | 0.78 (0.68 to 0.88) | 0.99 (0.81 to 1.21) | 0.90 (0.69 to 1.16) | 0.90 (0.70 to 1.17) | |
| External | 0.36 (0.32 to 0.40) | 0.74 (0.61 to 0.89) | 1.14 (0.89 to 1.45) | 1.05 (0.82 to 1.36) | |
| HSE and security | 0.92 (0.76 to 1.10) | 1.16 (0.87 to 1.54) | 1.10 (0.77 to 1.57) | 1.12 (0.78 to 1.62) | |
| Nuclear and scientific | 0.85 (0.71 to 1.01) | 1.09 (0.84 to 1.43) | 0.92 (0.66 to 1.29) | 0.96 (0.68 to 1.35) | |
| Office-based | 1.00 (baseline) | 1.00 (baseline) | 1.00 (baseline) | 1.00 (baseline) | |
| Project management | 0.92 (0.75 to 1.13) | 1.22 (0.89 to 1.68) | 1.01 (0.66 to 1.53) | 1.00 (0.66 to 1.51) | |
| Sex | Female | 1.00 (0.85 to 1.17) | 0.70 (0.58 to 0.86) | 0.71 (0.58 to 0.86) | |
| Job site | Head office | 0.74 (0.55 to 0.99) | 0.67 (0.46 to 0.97) | 0.70 (0.48 to 1.03) | |
| Power station 1 | 1.38 (1.10to 1.72) | 0.61 (0.47 to 0.80) | 0.58 (0.43 to 0.77) | ||
| Power station 2 | 0.40 (0.33 to 0.48) | 0.44 (0.34 to 0.56) | 0.38 (0.29 to 0.49) | ||
| Power station 3 | 2.54 (2.04 to 3.16) | 1.12 (0.85 to 1.47) | 0.90 (0.67 to 1.20) | ||
| Power station 4 | 0.74 (0.61 to 0.90) | 0.57 (0.45 to 0.73) | 0.42 (0.32 to 0.55) | ||
| Power station 5 | 1.34 (1.04 to 1.71) | 0.93 (0.69 to 1.27) | 0.97 (0.70 to 1.33) | ||
| Power station 6 | 0.39 (0.31 to 0.49) | 0.26 (0.20 to 0.34) | 0.22 (0.16 to 0.29) | ||
| Power station 7 | 1.00 (baseline) | 1.00 (baseline) | 1.00 (baseline) | ||
| Power station 8 | 4.16 (3.26 to 5.31) | 2.41 (1.79 to 3.24) | 2.05 (1.52 to 2.77) | ||
| Other | 0.93 (0.69 to 1.25) | 0.34 (0.24 to 0.48) | 0.31 (0.21 to 0.44) | ||
| Test reason | Symptoms | 85.70 (71.37 to 102.91) | 94.99 (78.29 to 115.24) | ||
| Close contact | 15.32 (12.75 to 18.40) | 16.73 (13.80 to 20.29) | |||
| Broader-defined work contact | 2.51 (1.89 to 3.33) | 2.66 (1.99 to 3.56) | |||
| Routine screening | 1.00 (baseline) | 1.00 (baseline) | |||
| Vaccination status | Per vaccination‡ | 0.97 (0.88 to 1.06) | |||
| Vulnerability status | Vulnerable | 0.78 (0.63 to 0.96) | |||
| Outage | During outage | 1.35 (1.12 to 1.63) | |||
| Site risk rating | 0/1 (lowest risk) | 1.00 (baseline) | |||
| 2 | 0.64 (0.50 to 0.82) | ||||
| 3 | 1.30 (1.00 to 1.69) | ||||
| 4 | 1.60 (1.11 to 2.31) |
*Adjusted for job category, sex and site in the table, and also test date, test type and age group (results not shown).
†Adjusted for all variables in the table plus test date, test type and age group (results not shown).
‡Up to fully vaccinated (two or more vaccinations).