Here’s how to make sense of changes to Arizona’s COVID-19 dashboard

PHOENIX – The Arizona Department of Health Services rolled out a variety of changes to how it presents data on its COVID-19 dashboard this week, some that could be confusing without further explanation.

ADHS also is planning additional system updates that will delay reporting for several key categories on Sunday and Monday.

“When the dashboard updates next on Tuesday, Oct. 19, it will have three days’ worth of reporting for cases, deaths and testing,” Interim Health Director Don Herrington said in a Thursday blog post.

“So there most likely will be an unusually high number of additions that morning. We expect daily additions to get back to normal levels in the days after.”

A variety of “enhancements” appeared with Wednesday’s daily dashboard update.

“One of the biggest changes you’ll notice is that on most pages you will see the most recent COVID-19 data,” Herrington said in a blog post that morning. “The dashboard will default to showing you the last six months to give a better picture of what is currently happening in Arizona.”

The new version of the site includes differences in the laboratory testing and vaccine administration sections that at first glance appear to show wholesale changes to previously reported data. However, it’s only the presentation that has changed, not the underlying data, according to ADHS.

Notably, the weekly percent positive rate for diagnostic testing, a key indicator of how much the virus is spreading in the community, dropped by about 3 percentage points in the default display of the testing page after Wednesday’s upgrade.

Herrington addressed the discrepancy in that morning’s post.

“Where the previous version of this section displayed two tabs, one showing data for unique individuals tested and one showing data for all tests conducted, the updated section is based solely on all tests conducted,” Herrington explained.

“This is a better indicator of laboratory demand and community transmission in Arizona.”

The default display for the weekly percent positive previously was the rate for unique individuals, which had been steady at about 12% in recent weeks. With new format featuring the rate for all tests conducted, the displayed weekly numbers are down to 9% for those weeks. The rate ticked up to 10% this week as of Friday’s update.

In another significant change, the vaccination page wound up showing fewer people getting shots in Arizona.

That’s because the site previously presented totals based on “county of administration,” which resulted in a single person being counted twice in some instances.

“If someone got vaccinated with a two-dose series in County A/County B, then this individual would be counted in vaccination metrics for County A and County B as both counties played a part in the vaccination efforts,” the ADHS data team explained in statement responding to KTAR News 92.3 FM’s inquiry about the discrepancy.

“This number grew as more people received additional doses and as state PODs [points of dispensing] opened and closed.”

Tuesday’s dashboard showed 4,271,482 people (59.4% of the state’s population, based on 7,189,020 residents) having received at least one dose of vaccine in Arizona and 3,781,360 people fully vaccinated (52.6%).

Each of those totals dropped by more than 100,000 upon Wednesday’s update, with the percentages falling accordingly.

The new site still has “county of administration” data in a second tab, but the default view shows data based on “county of residence,” which eliminates duplications and hence reduces the totals.

“With the new version “county of residence,” this issue doesn’t exist because people are listed as residents of only one county,” ADHS said.

“Regardless of where they received the vaccine, they will only be counted in only one jurisdiction. This accounts for the difference in the number of people vaccinated between the two tabs.”

As of Friday’s report, the dashboard showed 4,179,637 people receiving at least one shot (58% of the state’s population) and 3,665,084 fully vaccinated (51%). The nationwide rates were 65.8% with at least one dose and 56.8% fully vaccinated, per the Centers for Disease Control and Prevention.

“In addition to the new tab, there are two new data points on both dashboards: the percent of eligible individuals with at least one dose of vaccine as well as the percentage of individuals by age group,” Herrington wrote Wednesday about the vaccination section.

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