Arizona Notes

When Arizona reports no data, several days of data, or unusual data (such as decreases in values that should increase), our volunteers note it here on the date the anomaly occurred. We also note here changes in our own methodology that affect the data.

Arizona combines PCR and antigen tests in the total tests figure reported on the state’s dashboard

Arizona regularly reviews and removes duplicate records which may occasionally result in minor decreases of cumulative figures.

The Recovered data point we report for Arizona reflects the number of COVID-19 patients discharged from the hospital and therefore does not represent the total number of people who have recovered from COVID-19, since many people with COVID are never hospitalized.

Negative test results reported in our API and CSVs are calculated by subtracting Confirmed cases from Total PCR tests (people) in the absence of better data.

On March 1, 2021, Arizona announced via the official Arizona Department of Health Twitter that due to death certificate matching, Confirmed deaths increased by 1, and Probable deaths decreased by 2. As a result, Deaths (confirmed + probable) decreased by 1.

On February 22, 2021, Arizona announced via the Department of Health's official Twitter that no new deaths were reported. Additionally, there was a decrease of 3 deaths (confirmed and probable) due to death certificate matching.

On January 18, 2021 Arizona announced via the official Arizona Department of Health twitter that their reported Deaths (confirmed and probable) decreased by one due to de-duplication of the data.

On January 9, 2021, Arizona announced that the number of COVID-19 patients in ICU was incomplete on their COVID-19 dashboard, and we sourced Currently in ICU from the official Arizona Department of Health twitter.

On December 28, 2020, Arizona noted that due to the holiday weekend, multiple days of case reviews were completed, resulting in the data for December 28, 2020 being higher than usual. As a result, they reported a larger increase in Confirmed cases than Total PCR tests (people), which caused their Negative PCR tests (people), which is calculated as Total PCR tests (people) minus Confirmed cases, to decrease.

As of December 10, 2020, Arizona's total test results are drawn from our totalTestsViral field instead of calculated via positive+negative. We backfilled the data for March 2 2020 through December 8 2020 using the time-series posted on Arizona's dashboard as Diagnostic Tests Conducted.

On December 1, 2020, Arizona announced that figures reported on December 1, 2020, would be higher than normal due to a delay in case review and reported over the Thanksgiving weekend.

On October 6, 2020, the Arizona Department of Health Services announced that they were removing cases who had been admitted to a hospital but had not been hospitalized from their total hospitalization counts. This results in a decrease of Arizona's cumulative hospitalizations.

On September 18, 2020, Arizona reported a policy change in the way they count people with positive antigen testing results to comply with CSTE case definitions. This appears to have resulted in a large increase in probable cases and also likely the reason where a decrease in confirmed cases was observed.

On September 16, 2020, Arizona added antigen testing into its main totals figure. This appears to have raised its Total Tests (PCR) number more than usual.

From July 18–August 5, 2020, Arizona’s dashboard stopped displaying confirmed and probable breakdowns for Cases and Deaths, so we could not update Confirmed Cases, Probable Cases, Confirmed Deaths, or Probable Deaths during this period. We were still able to update the total data points for Cases (confirmed plus probable) and Deaths (confirmed plus probable). We will backfill the separate confirmed and probable case and death data if Arizona provides historical numbers.

On June 23, 2020, we updated our historical data for Cumulative hospitalized to match Arizona's dashboard data for "hospitalized by date admitted." Data for this metric is not typically reported until several days after admittance. Our daily updates will continue to compile Arizona’s overall number as of cumulative hospitalizations, regardless of date admitted.