Table 3. Incidence of COVID-19 among EMS providers by COVID-19 patient encounter and AGP status cohort, King County, Washington, February 16–July 31, 2020*.
| Cohort | COVID-19 patient encounter | 2–14 d exposure window | AGP status | EMS provider COVID-19 infection | Person-days at risk | Incidence/10,000 person-days (95% CI) | IRR (95% CI) |
|---|---|---|---|---|---|---|---|
| 1 | Yes | Yes | Yes | 1 | 8,582 | 1.17 (0.03–6.49) | 1.64 (0.22–12.26) |
| 2 | Yes | Yes | No | 0 | 26,583 | 0 (0.0–1.39) | 0 (0.0–1.50) |
| 3 | Yes | No | NA | 18 | 252,867 | 0.71 (0.42–1.13) | Referent |
| 4 |
Never |
NA |
NA |
11 |
240,245 |
0.46 (0.23–0.82) |
0.64 (0.30–1.36) |
| Post hoc | |||||||
| 1 and 2 | Yes | Yes | Y/N | 1 | 35,165 | 0.28 (0.01–1.58) | 0.40 (0.05–2.99) |
*AGP, aerosol generating procedure; COVID-19, coronavirus disease; EMS, emergency medical service; IRR, incidence rate ratio; NA, not available