Table 2.
Demographic characteristics of analysis sample
| Variable | Category | Test level | Individual level (at time of first test) | ||
| Number | % | Number | % | ||
| Total | 70 878 | 10 768 | |||
| Sex | Male | 63 197 | 89.2 | 9571 | 88.9 |
| Female | 7681 | 10.8 | 1197 | 11.1 | |
| Age group | 16–20 | 1012 | 1.4 | 189 | 1.8 |
| 21–25 | 4950 | 7.0 | 760 | 7.1 | |
| 26–30 | 7692 | 10.9 | 1184 | 11.0 | |
| 31–35 | 8775 | 12.4 | 1300 | 12.1 | |
| 36–40 | 7875 | 11.1 | 1237 | 11.5 | |
| 41–45 | 7037 | 9.9 | 1098 | 10.2 | |
| 46–50 | 7969 | 11.2 | 1231 | 11.4 | |
| 51–55 | 9727 | 13.7 | 1480 | 13.7 | |
| 56–60 | 9352 | 13.2 | 1348 | 12.5 | |
| 61–65 | 5106 | 7.2 | 715 | 6.6 | |
| 66–70 | 1225 | 1.7 | 193 | 1.8 | |
| 71+ | 158 | 0.2 | 33 | 0.3 | |
| Job category | Energy operations | 9067 | 12.8 | 1420 | 13.2 |
| Engineering | 12 752 | 18.0 | 1716 | 15.9 | |
| External contractors | 37 064 | 52.3 | 5710 | 53.0 | |
| HSE and security | 2621 | 3.7 | 373 | 3.5 | |
| Nuclear and scientific | 3175 | 4.5 | 460 | 4.3 | |
| Office-based | 4395 | 6.2 | 783 | 7.3 | |
| Project management | 1804 | 2.6 | 306 | 2.8 | |
| Job site | Head office | 1273 | 1.8 | 576 | 5.4 |
| Power station 1 | 2573 | 3.6 | 1099 | 10.2 | |
| Power station 2 | 5758 | 8.1 | 1164 | 10.8 | |
| Power station 3 | 5692 | 8.0 | 1011 | 9.4 | |
| Power station 4 | 15 333 | 21.6 | 1494 | 13.9 | |
| Power station 5 | 2926 | 4.1 | 981 | 9.1 | |
| Power station 6 | 2555 | 3.6 | 865 | 8.0 | |
| Power station 7 | 18 403 | 26.0 | 1869 | 17.4 | |
| Power station 8 | 15 516 | 21.9 | 1357 | 12.6 | |
| Other | 849 | 1.2 | 352 | 3.3 | |
| Test date | Q1–3 2020* | 304 | 0.4 | ||
| Q4 2020 | 2379 | 3.4 | |||
| Q1 2021 | 23 516 | 33.2 | |||
| Q2 2021 | 27 016 | 38.1 | |||
| Q3 2021 | 11 385 | 16.1 | |||
| Q4 2021 | 3933 | 5.6 | |||
| Q1 2022 | 1786 | 2.5 | |||
| Q2–3 2022† | 559 | 0.8 | |||
| Test type | PCR LAMP | 51 935 | 73.3 | ||
| Other PCR | 16 572 | 23.4 | |||
| Lateral Flow Test | 2371 | 3.4 | |||
| Test reason | Symptoms | 2773 | 3.9 | ||
| Close contact | 3174 | 4.5 | |||
| Broader-defined work contact | 2666 | 3.8 | |||
| Routine screening | 62 033 | 87.5 | |||
| Missing‡ | 232 | 0.3 | |||
| Vaccination status§ | Not vaccinated | 57 718 | 81.4 | ||
| Partially vaccinated (1) | 5078 | 7.2 | |||
| Fully vaccinated (2+) | 8082 | 11.4 | |||
| Vulnerability status¶ | Not vulnerable | 65 262 | 92.1 | 9819 | 91.2 |
| Vulnerable (Cat1-3) | 5616 | 7.9 | 949 | 8.8 | |
| Outage** | Not during outage | 35 580 | 50.2 | ||
| During outage | 35 298 | 49.8 | |||
| Site risk rating†† | 0/1‡‡ (lowest risk) | 1886 | 2.7 | ||
| 2 | 15 008 | 21.2 | |||
| 3 | 47 208 | 66.6 | |||
| 4 | 6776 | 9.6 | |||
| 5 (highest risk) | 0 | 0 | |||
*3 quarters combined due to low volumes (Q1=1, Q2=5, Q3=298).
†2 quarters combined due to low volumes, especially negative tests (Q2=390, Q3=169).
‡Kept in sample as not all models use test reason.
§Based on vaccination date being populated and dated at least 10 days before test.
¶Assumed to be not vulnerable if no vulnerability assessment took place.
**Based on statutory outage dates at the relevant site.
††Based on approximately weekly risk rating given to each site to determine COVID-19 safety protocols. If there was no risk rating for the week, the closest available was used. If site was Other, then average risk rating for the week was used.
‡‡Categories 0 and 1 were combined as there were only 73 in category 0.
LAMP, loop-mediated isothermal amplification.