Federal health authorities estimated in early April that more than 300,000 Americans could die from COVID-19 if all social distancing measures were abandoned, and subsequent estimates have pushed the number of possible deaths even higher, documents say. obtained by the Center for Public Integrity. Some outside experts even say that gloomy prospects may be overly optimistic.
Documents created by the Ministry of Health and Social Services explain the data and analysis the agency shares with other federal agencies to help shape their responses to the coronavirus.
While the White House Coronavirus Task Force cited other models created in academic institutions, the federal government has not released its own modeling efforts. The documents paint the most comprehensive picture of the assumptions underlying the government’s response to the pandemic.
The Trump administration is making plans to reopen the U.S. economy, and protesters are marching near state capitol buildings to demand that this happen quickly. But while overestimating the threat of the virus can lead to unnecessary job losses, underestimating it means more lives lost. The elderly and African-Americans, already disproportionately deceased, are particularly at risk, according to preliminary data.
The documents describe a series of scenarios showing how bad the coronavirus crisis could get, regardless of ongoing efforts to reduce it. This type of model provides a baseline against which to weigh mitigation efforts. The documents indicate that they are not intended to predict the exact course of the pandemic, but rather to help government officials plan.
“Models like this are also tools for distinguishing between possible futures and guiding your decisions to determine what you want to avoid and how best to avoid them,” said William Hanage, a Harvard University epidemiologist who was not part of the team that created the HHS documents. “We are trying to follow this moving target and give people the best advice.”
In the documents, the “best estimate” of how things will go without further mitigation indicates that cases and deaths of coronavirus would double approximately every five and a half days, on average, someone infected with coronavirus would spread the virus to 2.5 more people, and 0.5% of infected people with symptoms would die. Four of the seven experts interviewed by Public Integrity said that certain assumptions in the documents, such as the severity of the virus, were too rosy.
“Their model is too optimistic,” said Ashish Jha, director of the Harvard Global Health Institute. He said the government had reduced the death rate and ignored hospital overruns. “They are wrong in their analysis.”
Some have said that the government’s calculations are not sophisticated.
“This is exactly what a recruit would do,” said Juan Gutierrez, a mathematician who produces coronavirus models for the city of San Antonio. He said the government had underestimated the contagiousness of infected people without symptoms and that the documents began by assuming figures which should rather be proved by calculations.
Others believed that the assumptions in the documents were reasonable.
“What they have here seems to me now,” said Pinar Keskinocak, who leads a coronavirus propagation modeling team for Georgia Tech. “There are a lot of smart people out there who have a lot of modeling experience. I would be surprised if they do something strange. “
HHS and White House officials did not respond to requests for comment.
The power of social distancing
President Donald Trump unveiled April 16 step by step instructions so that states can resume a normal life, including gradually reducing social distancing measures Decisions on when and how to do so will require up-to-date scientific knowledge about how the virus spreads – the type of information described in HHS documents. Several states, including Florida and Texas, already are relax some restrictions.
“Reopening the United States will be a cautious, data-driven, county-by-county approach,” said Robert Redfield, director of the Centers for Disease Control and Prevention. Tweeter last week.
And while many experts agree that Americans have done a better job than expected in social distancing and enforcing home stay orders to date, HHS documents show just how much more painful the pandemic could be .
The path back to “normal” should be carefully and carefully calculated, said other public health researchers who are working on modeling the epidemic.
“Please do not rush to return to normal after the end of these on-site shelter orders,” said Keskinocak. She advised people to stay at home and quarantine if household members are sick, even after businesses reopen.
Best estimate scenario
The planning documents outline a “best estimate” scenario and four others – two worse and two better – using 11 parameters to describe the evolution of the virus and six estimates to help calculate the hospital beds and ventilators required. The documents indicate that the parameters are estimates from the best current data on transmission, mortality rates, doubling times and several other factors.
The figures for one of the documents expired in early April, while an almost identical document, although updated, indicates that its figures are up to date.
A table accompanying the old planning document shows that, according to HHS experts’ “best guess” calculations in early April, about one-third of Americans could be infected and show symptoms and more than 300,000 could die during the life of the pandemic if social distancing and other mitigation measures were to end immediately. This is well below previous estimates of 2.2 million deaths predicted by the influential model of the Imperial College and the 1.5 million to 2.2 million planned by the White House if the virus had not been controlled.
Three hundred thousand deaths without social distancing “would imply a very optimistic death rate,” said Jha. “This is not where the best estimates are today.”
Table shows that under the “most likely” scenario of health officials of a future without continued mitigation efforts, Florida, Maine, Puerto Rico, West Virginia, and Vermont would suffer the worst in terms deaths per capita. Florida – who Friday allowed some beaches to reopen if visitors did not get too close to each other, they would see more than 23,000 dead.
“We have our finger on spring right now,” said Gutierrez. “If we remove the finger, the spring jumps. So we will see many cases. “
The number of deaths in the other four scenarios ranges from approximately 94,000 to 1.8 million.
The updated HHS document revised some of the previous parameters, doubling the percentage of symptomatic people that the coronavirus would likely kill, from 0.25 to 0.5. It also increased the percentage of symptomatic people who should be hospitalized and the length of their stay.
The documents do not specify the number of deaths that the new higher mortality rate would cause in the best scenario. But a simple calculation by Public Integrity shows that it would be more than 600,000.
And although the changes are reasonable, experts say, some numbers may still be small.
“I am really shocked by the underestimation of hospital parameters simply because it seemed so well reported in China and Italy that there were patients who stayed long,” said Joseph Lewnard, epidemiologist at the University of California, Berkeley.
“The modeling must be done outdoors”
The early April document also used the impact of seasonal flu on different age groups to suggest how the coronavirus could affect them. The HHS changed this information in the most recent document, but previous use of the flu as a surrogate for the coronavirus has alarmed some experts.
“Flu and seizures are different illnesses,” said Hanage. “I hope that Covid-specific statistics will be used as assumptions for these models.”
The documents do not indicate to what extent social distancing could change the course of the virus from now on. But a separate federal planning document obtained by Public Integrity, which used parameters similar to those in the “best estimate” scenario, assumed that orders for on-site shelters would reduce the transmission of the virus by 75%.
Experts said government officials should publish their assumptions about coronaviruses so that everyone can have confidence in their work.
“There are certain mistakes that can be made, and if no one pays attention, they go unnoticed,” said Gutierrez. “Epidemiological modeling must be done outdoors. Usually you put a lid on the garbage. ”
Public integrity data editor Chris Zubak-Skees contributed to this story.