Ducey Models

Gov. Doug Ducey discusses Wednesday the issues and indicators he is reviewing in deciding if he will lift some of his restrictions on individual activities and business operations that are set to expire April 30.

PHOENIX — So how close is Arizona to finally hitting a peak in COVID-19 cases?

Well, it turns out that depends on whose numbers — and whose models — you believe.

While the reports by several different organizations paint different pictures, the positive news is that all suggest that Arizona will not run out of hospital space, intensive-care beds or ventilators. That had been the big concern.

But the question now goes to when Gov. Doug Ducey will conclude that the worst has passed and that the risk is sufficiently reduced so that he can begin slowly unwinding the restrictions he has imposed on everyday life in Arizona.

And the governor has to make some decisions soon: His stay-at-home order dissolves automatically April 30 unless renewed in whole or in part.

Ducey said he does take comfort in one common thread in all the predictions: None currently show the state running out of hospital and ICU beds or ventilators.

“Regardless of which one of these models happens to be right, we’re prepared,’’ he said.

For the moment, the governor is not saying what he intends to do about the stay-at-home order.

“We don’t know if we’re past the peak or before the peak,’’ he said.

“I’m not going to morph into a fortune teller and answer your question,’’ Ducey said in response to a query from Capitol Media Services. “We’re going to follow the facts and the data.’’

And the modeling?

“These are speculations that are educated speculations,’’ the governor said.

On the optimistic side — what health director Cara Christ called the “rosiest’’ — is the Institute for Health Metrics and Evaluation. Its most recent report suggests that the peak in daily deaths could occur by this weekend.

Longer term, it shows a declining death rate, probably hitting zero or close to that by June 13. But it still figures that 583 Arizonans eventually will die.

On a more practical level, the IHME model figures that Arizona’s use of hospital facilities won’t grow at all from this point forward.

By contrast, Christ said federal agencies, including the Centers for Disease Control and the Federal Emergency Management Agency, shared with her models they had built for Arizona based on projection formulas developed by John Hopkins University.

Christ did not share any death data from that model, saying that she has not received permission to provide how they got to the numbers. But she said that model predicts that hospital beds and medical equipment use will not peak until around June 11.

“This model appears to be the most realistic and the predictions are reassuring,’’ the director said.

What makes that particularly relevant is that Christ said that is built on the presumption that the various gubernatorial orders will self-destruct as scheduled April 30.

That finding could prove particularly relevant to any decision Ducey makes in the next week, as it suggests that extending “mitigation strategies’’ beyond the end of the month might results in an earlier peak — and, potentially, fewer cases of the virus and fewer deaths.

Others have their own proposals.

One, said Christ, was developed by her agency partnering with the University of Arizona and Arizona State University for a “more targeted, Arizona-specific model.’’

It produced its own range of infections, with a mid-range prediction of about 88,466. But what it predicts is that the peak will not occur until about the middle of next month and peak hospital bed and ICU usage around May 22.

And if that’s not enough, consider the model produced by COVIDActNow,org. It was created by volunteers who partnered with epidemiologists and data scientists to look at not just the raw numbers but the effects of intervetion.

Based on current trends, that model predicts that 4% of Arizonans eventually will contract the virus, with a total of 2,000 deaths.

But the model also has a warning of sorts. It says if restrictions are lifted, up to 70% of Arizonans could be infected in the next three months, with 65,000 people eventually dying.

This model also does some county-by-county breakdowns.

In Pima County, for example, even with no easing of restrictions, it predicts 6% of the population will contract COVID-19. By contrast, maintaining stay-at-home provisions will still mean 3% infection rate in Yavapai County, 2% in Mohave County and the same for Cochise County.

At the other extreme, projections based on current trends for Navajo County show a 12% infection rate in the coming three months.