Table 4

ORs and 95% CIs for risk of testing positive on COVID-19 test

ExposureCategoryCrude job type association
(n=70 878)
Base model*
(n=70 878)
Base model*+test reason
(n=70 646)
Final model†
(n=70 646)
Job categoryEnergy operations0.98 (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)
Engineering0.78 (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)
External0.36 (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 security0.92 (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 scientific0.85 (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-based1.00 (baseline)1.00 (baseline)1.00 (baseline)1.00 (baseline)
Project management0.92 (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)
SexFemale1.00 (0.85 to 1.17)0.70 (0.58 to 0.86)0.71 (0.58 to 0.86)
Job siteHead office0.74 (0.55 to 0.99)0.67 (0.46 to 0.97)0.70 (0.48 to 1.03)
Power station 11.38 (1.10to 1.72)0.61 (0.47 to 0.80)0.58 (0.43 to 0.77)
Power station 20.40 (0.33 to 0.48)0.44 (0.34 to 0.56)0.38 (0.29 to 0.49)
Power station 32.54 (2.04 to 3.16)1.12 (0.85 to 1.47)0.90 (0.67 to 1.20)
Power station 40.74 (0.61 to 0.90)0.57 (0.45 to 0.73)0.42 (0.32 to 0.55)
Power station 51.34 (1.04 to 1.71)0.93 (0.69 to 1.27)0.97 (0.70 to 1.33)
Power station 60.39 (0.31 to 0.49)0.26 (0.20 to 0.34)0.22 (0.16 to 0.29)
Power station 71.00 (baseline)1.00 (baseline)1.00 (baseline)
Power station 84.16 (3.26 to 5.31)2.41 (1.79 to 3.24)2.05 (1.52 to 2.77)
Other0.93 (0.69 to 1.25)0.34 (0.24 to 0.48)0.31 (0.21 to 0.44)
Test reasonSymptoms85.70 (71.37 to 102.91)94.99 (78.29 to 115.24)
Close contact15.32 (12.75 to 18.40)16.73 (13.80 to 20.29)
Broader-defined work contact2.51 (1.89 to 3.33)2.66 (1.99 to 3.56)
Routine screening1.00 (baseline)1.00 (baseline)
Vaccination statusPer vaccination‡0.97 (0.88 to 1.06)
Vulnerability statusVulnerable0.78 (0.63 to 0.96)
OutageDuring outage1.35 (1.12 to 1.63)
Site risk rating0/1 (lowest risk)1.00 (baseline)
20.64 (0.50 to 0.82)
31.30 (1.00 to 1.69)
41.60 (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).