COVID-19 summary

Data notes

Data sources

• COVID-19 outcomes and immunizations data are from the Washington Department of Health.
• Population estimates come from the 2020 Office of Financial Management and American Community Survey.
  
   

Reporting delays and limitations 

Due to reporting delays (data lags), data is preliminary and subject to change. Data will be refreshed retrospectively with ongoing data quality improvements. 

The following dates are used to report each COVID-19 metric: 

• COVID-19 hospitalizations: hospital admission date
• Deaths due to COVID-19: date of death

Due to reporting delays, the most recent month of deaths due to COVID-19 is considered incomplete and is excluded from our reports.

Hospitalizations and death data 

COVID-19 hospitalization counts and rates include incidental COVID-19 hospitalizations (hospitalizations for injury or illness not primarily related to COVID-19). Deaths due to COVID-19 are counted for individuals where the outcome was due to COVID-19 illness or were COVID-19 related.

Washington State Department of Health and PHSKC implemented a new definition of COVID-associated deaths for any death that occurred on or after January 1, 2023. COVID-associated deaths are identified based on COVID-19 keywords listed on the death certificate and no longer require a positive COVID-19 PCR or antigen test result. This definition was adopted to align with national standards and guidance. Learn more about the updated death definition (293 KB).

Before January 1, 2023, deaths among persons with positive COVID-19 PCR or antigen results were investigated to determine if the cause of death was confirmed or suspected to have been related to COVID-19. Death investigations were conducted by reviewing the decedent's death certificate and, when necessary, medical record information. If COVID-19 was ruled out as a cause of death, these deaths were removed from our dashboards and reports. Death certificates are typically filed within 2 weeks of the date of death; however, those can take up to a year to be finalized. 

Average rates 

The weekly average rate is used to adjust for daily variations, which may be large among smaller populations. It is determined by first calculating the rate for each week in each time frame (i.e., the past 6 months). Then, the average of the weekly rates for the time frame is taken. 

Age adjustment 

When we compare rates of COVID-19 outcomes between different groups of people, we use age adjustment. Age adjustment is a common statistical method that accounts for differences in the age profiles between different groups to support a more representative comparison. This makes it easier to compare COVID-19 outcomes for different race and ethnicity groups even though some of the groups have more older or younger people than other groups. 

Age adjusted rates provide a way to account for differences and compare groups meaningfully. Learn more about age adjustment.

Race and ethnicity

We calculate estimated rates for race and ethnicity. Individuals of Hispanic/Latina/o/x ethnicity, race/ethnicity are categorized as "Hispanic", while non-Hispanic/Latina/o/x ethnicity individuals are categorized as the race they selected. Individuals who selected multiple races are categorized as "multi-racial". 

Sex and gender

The data on sex is representative of sex assigned at birth. Non-binary and gender diverse data are presented where available and is dependent of the data source. While we calculate rates for some sex and gender categories, we do not have population estimates – and therefore rates – for those who identify as non-binary.