Supplemental Table 3.
Infection rates in pregnancy—sensitivity analysis estimating severe acute respiratory syndrome coronavirus 2 infection rates using WA-DOH case counts and 2018 birth data
| ACH region | WA-DOH–reported cases in pregnancy |
Washington State: 20–39 y |
RR |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cases in pregnancya |
Estimated deliveries during the study periodb n |
SARS-CoV-2 infection rate per 1000 deliveries |
Casesc |
Populationd n |
SARS-CoV-2 infection rate per 1000 |
|||||||
| n | (%) | Rate | (95% CI) | n | (%) | Rate | (95% CI) | RR | (95% CI) | |||
| Better Health Together or North Central | 23 | (6.6) | 3376 | 6.8 | (4.3–10.2) | 1746 | (11.5) | 214,300 | 8.1 | (7.8–8.5) | 0.8 | (0.5–1.3) |
| Greater Columbia | 135 | (39.0) | 3146 | 42.9 | (3.6–5.1) | 5459 | (35.8) | 193,851 | 28.2 | (27.4–28.9) | 1.5 | (1.3–1.8) |
| King | 98 | (28.3) | 8112 | 12.1 | (9.8–14.7) | 4274 | (28.0) | 744,386 | 5.7 | (5.6–5.9) | 2.1 | (1.7–2.6) |
| North Sound | 60 | (17.3) | 4755 | 12.6 | (9.6–16.2) | 1752 | (11.5) | 325,671 | 5.4 | (5.1–5.6) | 2.3 | (1.8–3.0) |
| Pierce | 20 | (5.8) | 3821 | 5.2 | (3.2–8.1) | 1173 | (7.7) | 239,814 | 4.9 | (4.6–5.2) | 1.1 | (0.7–1.7) |
| SW Washington State Regional Health, Olympic, or Cascade Pacific Action Alliance | 10 | (2.9) | 5458 | 1.8 | (0.9–3.4) | 834 | (5.5) | 358,226 | 2.3 | (2.2–2.5) | 0.8 | (0.4–1.4) |
| Washington State total | 346 | 28,682 | 12.1 | (10.8–13.4)e | 15,238f | 2,076,248 | 7.3 | (7.2–7.4) | 1.7 | (1.4–2.2)g | ||
Adapted from Washing State Department of Health and Washing State Office of Financial Management.18,22
ACH, Accountable Communities of Health; CI, confidence interval; COVID-19, coronavirus disease 2019; RR, rate ratio; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; WA-DOH, Washington State Department of Health.
Lokken et al. Severe acute respiratory syndrome coronavirus 2 infection rate in pregnancy. Am J Obstet Gynecol 2021.
Case counts of confirmed SARS-CoV-2 cases among females aged 18 to 50 years who were pregnant at the time of infection were provided by the WA-DOH from March 1, 2020, to June 30, 2020. Pregnancy status was ascertained through case interviews or by local health jurisdiction investigation. In 35% of SARS-CoV-2 case records among females aged 18 to 50 years, pregnancy status was unknown or missing pregnancy
Statewide live births were estimated from March 2020 to June 2020 using the Washington State 2018 birth data specifically by estimating 4 months of annual births using the ACH-specific and overall total births from 2018 birth dashboard (Birth Certificate Data, 2000–2018, Community Health Assessment Tool at https://www.doh.wa.gov/DataandStatisticalReports/HealthDataVisualization/BirthDashboards/AllBirthsACH)
Case data were calculated from March 1, 2020, to June 28, 2020 (closest available date to June 30, 2020) using the “COVID-19 in Washington State: Confirmed Cases, Hospitalizations and Deaths by Week of Illness Onset, County, and Age” data set available from the WA-DOH at https://www.doh.wa.gov/Emergencies/COVID19/DataDashboard. Counts include females and males
Population estimate calculated using the 2019 postcensal population estimates from the Washington State Office of Financial Management
Infection rates were calculated with Poisson regression with additional clustering by ACH region for the statewide estimate
The overall number of SARS-CoV-2 cases through June 28, 2020, was 15,238, but 20 cases were not assigned to an ACH region
The statewide rate ratio is an ACH-weighted state estimate.