weather icon Clear

Modeling Nevada’s COVID-19 outbreak, deaths no simple feat

Updated April 2, 2020 - 8:51 am

COVID-19 could kill 800 people in Nevada by August, with the daily death toll peaking at 26 on April 18, according to a new model forecasting the spread of the new coronavirus.

Nevada’s peak use of hospital resources would occur two days later, the model predicted Friday. By then, Nevada’s hospitals would need more than 500 additional beds than they currently have and more than 200 more beds in intensive care units.

The model, created by the Institute for Health Metrics and Evaluation at the University of Washington, is one of many attempting to chart the path that the new coronavirus will take in the U.S. and in Nevada. But it has taken on prominence since being referenced a week ago by Dr. Deborah Birx, the White House’s coronavirus response coordinator.

“No state, no metro area, will be spared,” Birx said in an interview on NBC’s “Meet the Press.” “Every metro area should assume they could have an outbreak similar to New York’s,” where hospitals have been overwhelmed by a surge in cases and deaths.

Early last week, the model, which provides state-by-state forecasts, gave some reason for optimism in Nevada: The trajectory appeared to be improving, with projected total deaths dipping to just above 500 and a shortage of just 60 ICU beds.

That changed Wednesday, however, when the model shifted to project 921 COVID-19 deaths in the state and again predicted a need for about 1,000 more hospital beds than currently available.

It’s not clear what triggered the change, and staff at the institute did not respond to requests for comment. However, the model factors in emergency measures taken by officials to slow the spread of the disease and refines estimates as better data becomes available over time.

The fluctuation in predictions underscores the limitations of such models: They are only as good as their underlying assumptions, which in this instance are cloudy with so much still uncertain about the virus, including how prevalent it is in the U.S. and how deadly, and the degree to which emergency measures are helping. Put another way, the model must attempt to predict not only the behavior of the virus but the diligence with which humans follow recommended precautions to defeat it.

Bracing for the peak

It is also unclear what projections state and local governments are using as they implement new restrictions, such as Nevada Gov. Steve Sisolak’s stay-at-home directive issued Wednesday to slow the spread of the virus, which as of Friday had infected more than 1,500 and killed 43 in the state.

“Nationally there are a variety of models that can be used to potentially predict COVID-19,” said Meghin Delaney, a spokeswoman for state government’s Nevada Health Response. “The Department of Health and Human Services is reviewing all available resources, along with Nevada’s case information, in order to have the most up-to-date information to support Nevadans in our response to COVID-19.”

Delaney said that based on current estimates, Nevada will need “hundreds of thousands of N95 masks, surgical masks, gloves, and hospital gowns over the course of the next 30 days.”

As of Friday in Clark County, the location of the majority of Nevada’s cases in the state, about 29 percent of the 1,279 people testing positive required hospitalization, including those who later died, according to data from the Southern Nevada Health District’s website.

“The Southern Nevada Health District is working with our local, state and federal partners to be prepared to address hospital overflow and obtain resources,” spokeswoman Jennifer Sizemore said. “We are working to put these resources in place as quickly as possible.”

Both Delaney and Sizemore declined to provide estimates for when the disease might peak or for the total number of deaths expected.

But the Las Vegas Valley’s largest hospitals say they are preparing for local COVID-19 cases in Nevada to peak as soon as mid-April.

These include University Medical Center, Valley Health System’s six local hospitals and HCA Healthcare, parent company of four local acute-care hospitals, according to spokespersons.

UMC is also analyzing “multiple predictive models from trusted sources,” spokesman Scott Kerbs said. He did not provide specifics on the models being used by the hospital.

Modeling flaws

The Institute for Health Metrics and Evaluation’s model on Friday predicted nearly 94,000 deaths from COVID-19 nationwide by early August, more than 12,400 above what it was projecting a week ago.

Still, the estimate was toward the lower end of the spectrum for modeling of the disease’s impact.

Birx said Tuesday at a White House briefing that deaths in the U.S. could number between 100,000 and 240,000, even with emergency measures in place.

Some models have forecast the U.S. death toll to exceed 2 million — a possibility, White House officials have said, if the U.S. fails to follow aggressive measures to slow the spread.

But the problem with predictive models is that “they are only as good as their assumptions and parameters, and right now, these are all unknown,” said Brian Labus, an assistant professor of epidemiology at UNLV’s School of Public Health.

The variables for which there are only estimates include how prevalent the virus is in the U.S. population, how readily the virus spreads from person to person and what the actual death rate will be. Further complicating matters is factoring into the calculations the impact of various emergency measures, such as social distancing and closing schools and businesses.

“I think the models are good at saying that one particular course of action is better than another, but they are not good at predicting the course of this outbreak,” said Labus, who serves on the governor’s medical advisory team for COVID-19.

Far more dire than the institute’s forecast, a model published by COVID Act Now estimated as recently as Wednesday that the disease kill could kill 47,000 people in Nevada, even with social distancing in place for three months. The organization, headed by a software engineer for Google, saw hospitals in the state becoming overwhelmed in mid-April.

The model predicted even more deaths — 62,000 — without social distancing and just 2,000 deaths if sheltering in place were strictly observed for three months.

Possible toll lowered

However on Friday, after the governor’s stay-at-home directive, the model forecast far fewer fatalities: 14,000 deaths if compliance is poor, and 4,000 deaths with strict compliance. With poor compliance, hospitals could become overwhelmed by May 12, and hospitalizations peak at nearly 17,000 on June 19. It cautioned that there could be another spike in illness when social distancing measures stop.

Labus said that the COVID Act Now’s most dire forecasting assumed that 70 percent of people would become infected and a death rate of 3 percent, both of which are at the high end of estimates. It also makes assumptions in terms of the degree to which social distancing will help matters — “another thing I don’t think we can agree on,” he said.

Another fault of modeling is that it typically treats Nevada as a single entity despite differences among urban, suburban and rural areas. Labus said, noting that infection rates and health care delivery will vary from community to community.

What many of the models have in common is that they project a three-month cycle for the disease, Labus said, and that “it’s going to get worse before it gets better.”

The models all raise the specter of not enough hospital beds, especially in intensive care units. But Labus said that’s just one piece of the puzzle.

“What’s going to happen if we have more patients than we have supplies to take care of them?” Labus asked rhetorically, referring to protective gear for medical personnel, ventilators for patients and other essential equipment. “Thinking that that’s something potentially we’re going to have to deal with is really terrifying.”

Contact Mary Hynes at mhynes@reviewjournal.com or 702-383-0336. Follow @MaryHynes1 on Twitter. Contact Michael Scott Davidson at sdavidson@reviewjournal.com or 702-477-3861. Follow @davidsonlvrj on Twitter.

Don't miss the big stories. Like us on Facebook.
Politics Videos
Nevada gyms, bars that do not serve food can reopen Friday - VIDEO
Nevada Gov. Steve Sisolak on Tuesday evening said Phase 2 of the state’s Nevada United: Roadmap to Recovery will begin on Friday. (James Schaeffer / Las Vegas Review-Journal)
Nevada Rep. Horsford admits to having affair - VIDEO
Nevada Congressman Steven Horsford admitted to having an affair with Gabriela Linder, a former intern for Sen. Harry Reid. Linder detailed her account of the affair in a podcast she called, "Mistress for Congress." (Heidi Fang/Las Vegas Review-Journal)
Sisolak says businesses will begin reopening under phase 1 - VIDEO
The first phase of reopening Nevada’s businesses will begin Saturday, May 9, Gov. Steve Sisolak said Thursday. (James Schaeffer / Las Vegas Review-Journal)
Joe Biden denies Tara Reade's sexual assault allegation - VIDEO
The former senate aide claims Biden assaulted her in 1993 when he was a senator. Biden first denied the accusations via a public post on Medium. (Las Vegas Review-Journal)
RJ interview with Sisolak on the reopening plan for Nevada - VIDEO
The Las Vegas Review-Journal interviewed Nevada Governor Steve Sisolak on the plan for reopening Nevada during the coronavirus pandemic. (James Schaeffer / Las Vegas Review-Journal)
Sisolak reacts to Goodman CNN interview- VIDEO
Las Vegas Mayor Carolyn Goodman repeated her call to immediately reopen businesses during an interview with CNN’s Anderson Cooper on Wednesday, leading to a reaction from Nevada Governor Steve Sisolak. (James Schaeffer / Las Vegas Review-Journal)
Sisolak praises Nevadans for staying at home, saving lives - VIDEO
Gov. Steve Sisolak said Thursday it’s still too early to know when the state’s COVID-19 shutdown orders could be lifted or when businesses could start to reopen their doors. (James Schaeffer / Las Vegas Review-Journal)
Trump gives governors 3-phase approach to open US - VIDEO
President Donald Trump declared victory in America’s war against the “invisible enemy” as the president’s Coronavirus Task Force released “Opening up America Again” guidelines. (James Schaeffer / Las Vegas Review-Journal)
Trump names Jacky Rosen to task force on reopening economy - VIDEO
President Donald Trump named Sen. Jacky Rosen, D-Nev., to be a member of his Opening Up America Again Congressional Group Thursday to advise him on coronavirus policy. (James Schaeffer / Las Vegas Review-Journal)
Bernie Sanders endorses Joe Biden for president - VIDEO
On April 13, former presidential hopeful Bernie Sanders announced his official endorsement of former Vice President Joe Biden. (Las Vegas Review-Journal)
Bernie Sanders drops out of 2020 Democratic race for president - VIDEO
Sen. Bernie Sanders of Vermont officially announced an end to his 2020 presidential bid on Wednesday. (Las Vegas Review-Journal)
Democratic National Convention postponed - VIDEO
The Democratic National Convention was set to take place over four days in the middle of July. Democratic officials have now confirmed the convention will take place the week of Aug. 17. (Las Vegas Review-Journal)
Henderson allows immediate sale of alcohol with curbside pickup - VIDEO
The city of Henderson decided Thursday evening to allow alcohol to be sold by restaurants as part of their curbside pickup service during the COVID-19 crisis. (James Schaeffer / Las Vegas Review-Journal)
Sisolak signs order banning any gathering of 10 or more people - VIDEO
Gov. Steve Sisolak on Tuesday signed a new order banning any gathering of 10 or more people in Nevada in another step the state has taken to slow the spread of the new coronavirus. (James Schaeffer / Las Vegas Review-Journal)
Takeaways from the president's daily briefing on coronavirus - VIDEO
RJ Washington correspondent Debra Saunders talks about today's daily White House news conference regarding the coronavirus outbreak, Friday, March 20, 2020. (Renee Summerour/Las Vegas Review-Journal)
Judicial Department 5 Debate - Video
The Las Vegas Review-Journal hosts a debate between the 3 candidates running for Department 5 in Clark County District Court. Participating are Veronica M. Barisich, Terry A. Coffing and Blair Cowan Parker.
Trump cancels Las Vegas trip because of ‘coronavirus outbreak’ - VIDEO
President Donald Trump canceled planned travel to Las Vegas ‘out of an abundance of caution’ amid virus outbreak. (James Schaeffer / Las Vegas Review-Journal)
Trump signs $8.3 billion coronavirus package - VIDEO
President Trump signed a bill providing $8.3 billion in emergency funding to combat the coronavirus outbreaK, Friday, March 6, 2020. (Las Vegas Review-Journal)
Sen. Cortez Masto shows support for Judge Togliatti - VIDEO
Sen. Catherine Cortez Masto shows her support for senior state District Court Judge Jennifer Togliatti to be appointed to the federal bench in Nevada. (Sen. Catherine Cortez Masto)
Sen. Rosen supports Judge Togliatti - VIDEO
Sen. Jacky Rosen shows her support for Nevada Judge Jennifer Togliatti to be appointed to the federal bench. (Sen. Jacky Rosen)
MSNBC’s Chris Matthews resigns following series of controversies - VIDEO
The "Hardball" host announced his departure Monday night, March 2, 2020, effective immediately. The anchor recently came under fire for comparing Sen. Bernie Sanders’ victory in the Nevada caucasus to the Nazi conquest of France in 1940. (Las Vegas Review-Journal)
Candidates file for office in Clark County - VIDEO
Amy Klobuchar drops out of 2020 presidential race - VIDEO
On March 2, campaign officials announced Amy Klobuchar’s decision to suspend her presidential bid. The news comes on the eve of Super Tuesday and just one day after Pete Buttigieg also announced his decision to depart from the race. (Las Vegas Review-Journal)
Virgin Orbit fails on 1st rocket launch attempt

The inaugural launch had appeared to be going well until moments after the rocket was dropped from beneath the left wing of the jumbo jet dubbed Cosmic Girl.

NASA’s 1st home launch in decade 1 week away

NASA test pilots Doug Hurley and Bob Behnken flew to Florida from Houston aboard one of the space agency’s jets.