Data Downloads
Reports
Data Notes
December 6, 2020: Increased laboratory report volumes and a temporary slowdown in system processing have impacted reported cases, deaths, and testing volume. Today’s total case counts may include up to 970 duplicates that have not been processed, and some positive laboratory reports received over the past two days have not been processed and are not included in today's updates. The overall impact is that reported case counts are likely lower than true case counts. We also resumed reporting negative COVID test results on December 4. However, test data from November 21, 2020 through today are not yet complete. Due to a processing error identified December 4, as many as 90 deaths added to our dashboards as of Friday December 4 are incorrectly classified as due to COVID-19. Death data should be interpreted with caution and corrections will be made by Monday December 7, 2020. The Epidemiologic Curves tab is the most accurate representation of COVID activity and is updated daily as new cases are identified and duplicates are resolved.
Technical Notes
Time delays and lags
Minor time delays in the collection of laboratory testing data, confirming cases, hospitalizations, and deaths occur regularly due to processing and reporting variation between data sources. This variation is due to differences in individual actions, laboratory capacities, and case confirmation and reporting processes.
After analyzing time lags between steps, the Washington State Department of Health (DOH) increased the period of incomplete reporting for most metrics to 10 days to ensure that 90% of data are accounted for in our posted numbers. For each metric shown on a time trend, the incomplete data period is shown in light gray. We provide a Learn More link with more detail on the period of incomplete data.
Number of infections
Public health experts agree that the true number of people who have been infected with COVID-19 in Washington greatly exceeds those that have been laboratory-confirmed. It is very difficult to know exactly how many people in Washington have been infected to date, since most people with COVID-19 experience mild illness and testing is still not widely available.
Cases
Effective June 16, 2020, Washington State Department of Health (DOH) uses the date of an individual’s first positive lab result as the case date. Previously, the date a case was reported to DOH was used as the case date. Our current approach provides a more accurate designation of case confirmation dates while shifting less than 10% of case counts by date, most noticeably for cumulative case counts and graphics.
Testing
Two important data issues continue to affect results presented on the testing tab: 1) the delayed entry of negative lab results into our data system; and 2) the lack of an assigned county for about 21% of negative test results. These issues impact some counties disproportionately. Washington State Department of Health (DOH) continues to work on a sustainable solution.
Effective August 25, 2020, DOH changed the methodology for reporting test results. The total number of tests are now reported instead of the total number of individuals tested. New positive and negative test counts include all molecular tests (by specimen collection date) of individuals who have not previously tested positive. Multiple test results from the same day are counted only once and we exclude repeat tests on an individual after the first positive result. This methodology has been applied to the entire dashboard timeframe. The changes in our testing methodology did not affect dashboard testing trends.
Deaths
Deaths are reported to the state by health care providers, medical examiners/coroners, local health departments, and others. For this reason, the statewide count of deaths often lags behind the counts of local health departments.
Effective August 28, 2020, the Washington State Department of Health (DOH) stopped publishing COVID-19 death counts on weekends. COVID-19 death counts are published Monday through Friday. DOH adds the counts collected on weekends to the following Monday and Tuesday reports.