The latest projections: Where they come from, and what they mean

The dome of the Kentucky state capitol is lit green in memory of those who have died of COVID-19. (Eric Crawford photo)

Years ago there was a board game based on a book titled, “The Worst-Case Scenario Survival Handbook.” The popular book, which then became a series of books, provided tips for handling various catastrophes. It was entertaining, because most of the things in the book were things most of us would never encounter. And it brought a certain comfort in knowing what you might need to do if the worst did, indeed, happen.

The worst-case scenario is a staple of planning, from business to military to government. Prepare for the worst, the saying goes, then hope it doesn’t happen. It’s sound strategy.

But in the time of the novel coronavirus COVID-19, the worst-case scenario is worth keeping in perspective. As seen by the rapid about-face by President Donald Trump over the weekend — which he entered talking about having some of the country back to work by Easter and ended by extending nationwide social distancing guidelines through the end of April — models for the spread of the virus are influential, but can vary widely.

Yet, the public sees little detail when it comes to these projections.

When Dr. Deborah Birx, response coordinator for the White House Coronavirus Task Force, in talking about the coming weeks and what they might bring, said last week that models the government was looking at didn’t suggest some of the “doomsday” tone it was seeing in the public – or in the earliest projections — it set off a firestorm. But her statement wasn’t really controversial. States are planning for the worst-case scenario. But the worst-case projections can change over time with social distancing measures in place, and the worst case isn’t, by definition, the most likely case in any set of projections.

Many media feed on worst-case scenarios. They are compelling, heighten the sense of crisis and drama and, maybe most important, they sell. Birx responded to some of the more sensational estimates with this statement: “There is no model right now — no reality on the ground where we can see that 60% to 70% of Americans are going to get infected in the next eight to 12 weeks. I want to be clear about that.”

She stressed responsiveness as a key in dealing with the outbreaks in the more populated areas. If one hospital is short on equipment or bed space, others nearby would need to respond. They would need to be well coordinated to make the most of equipment available, even as state and federal governments work to provide more.

But just because she veered away from early worst-case scenario projections doesn’t mean the current models aren’t of great concern. She and Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases since 1984, discussed the latest projections with Trump, prompting him to extend the federal social distancing guidelines.

“Dr. Birx and I spent a considerable amount of time going over the data, why we felt this was the best choice for the U.S., and the president accepted it,” Fauci said.

Birx added that people, “have to know that we built this (response) on scientific evidence and the potential to save hundreds of thousands of American lives.”

The latest projections they shared, from the University of Massachusetts at Amherst, the CDC and elsewhere, say as many as 200,000 Americans could die by the end of the year, even with the measures that have been put into place in many states. In other words, that could be a best-case scenario.

UMass released its new findings last week, and a new set of data was released by the Imperial College of London, revising its projections in light of social distancing measures taken. That study suggests that even with the measures in place, 500,000 could die in North America.

But even these projections are somewhat compromised by a lack of testing and by an incomplete understanding of how this virus works.

Azra Ghani, chair of infectious disease and epidemiology at Imperial College, said in a podcast produced by the college that the institution’s projections still are hampered by incomplete information.

“We don’t really have any sense in the role of children in transmission,” she said. “We know that children are at relatively low risk of developing disease and we don’t see that many cases compared to the size of the underlying populations in anyone under the age of 20. What we don’t know is whether they’re getting infected and potentially transmitting the disease to others or whether they’re completely immune to it or mostly not susceptible. Scientifically, that is challenging. . . . Until we do this, we won’t really have a good assessment.”

It will take a test that reveals whether a person has been infected in the past to know that, and such tests are still weeks away from widespread use in the U.K., and potentially even further away elsewhere.

In other words, the projections are just highly educated guesses, but they are all that governments have to go on, in the absence of more widespread testing.

New York governor Andrew Cuomo has been dealing with dire projections since the first cases arrived in New York. Like every governor, he has been working to “flatten the curve” in his own state.

“We don’t do the projections ourselves,” Cuomo said. “We have Cornell-Weill Medical Center, the CDC does projections, we have McKensie & Company that we hired to do projections. So there are a number of firms that do these projection models, and they go back and study China and South Korea and everything else. And they have models. The models, some of them are all over the place. So we do the best we can to pick a reasonable model, not the highest, not the lowest, and plan for that model and plan for that apex. That’s where we got from Day 1, (New York needs) 140,000 hospital beds, 40,000 ICU beds, that’s from that model at the apex. Well, you don’t need 140,000 hospital beds today. Of course not, we need them at the apex. But that’s where we got the original projections. Then you have the actuality. You can see the day-to-day, how many come in, how many go out, the discharge rate, the death rate. And that’s what we’re plotting. And then they take every day and put it against their projections. But you still only have a projection. They still can’t tell you . . . . They’re watching for a slowing of the number of cases. And when you see the increase in the number of cases slowing, then you are theoretically reaching the apex. Otherwise, you just watch it day to day.”

In Kentucky, Gov. Andy Beshear, like most governors, has talked relatively little publicly in terms of specific projection numbers. A search for more detailed numbers turned up a set of projections by the Institute for Health Metrics and Evaluation in Seattle. This model projects Kentucky with 585 deaths through August 3 — given its early action and restrictive measures — including a peak of 1,148 hospital beds needed and 172 ICU beds.

These projections, it should be noted, run somewhat lower nationally (82,141 deaths through early August) than those projections cited by Facui and Birx – and do not run through the end of the year. They do, however, provide a range, and show projected number of cases and fatalities without intervention versus scenarios with intervention. And in terms of deaths through the end of the year, it’s worth noting that those surveyed in the most recent UMass study projected a 73 percent probability of another breakout of COVID-19 in the fall.

So what sense do we make of all these? It’s tough to know what to think, without more information. But it’s information that the public needs.

“I think that’s very important, because it’s good for the public to be aware of all of the data that are being generated, even if some of these figures can sometimes appear to be somewhat alarming,” Ghani said.

When the CDC awarded $3 million to a research team at the UMass School of Public Health and Health Sciences to develop a data-based flu forecasting center, Nicholas Reich, director of the center, said, “If we can communicate the data effectively, we might change behavior.”

As more information comes into view, it’s incumbent on public officials to share more about expectations, and on media to report the entire range – not just the worst case projections.