Living Dangerously (part 4)

May 24, 2020

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As of this Memorial Day weekend, the US death toll from covid-19 continues to rise at a slower rate, both in absolute numbers and as a percentage. This week’s 8,812 new deaths represented an increase of 10%, compared to a increase of 10,239 (13%) the previous week. Slower increase was the story in most states, despite the easing of restrictions on public activity. All ten of the states with the highest percentage increase the previous week (listed in the previous post) had a lower rate of increase this week. A few other states, however, experienced a higher percentage increase this week: Arkansas, Indiana, Kentucky, North Dakota, Rhode Island, Utah and Wyoming. The good news is that no state has been experiencing a sustained acceleration of deaths.

Two words of caution, however. Some states have serious local outbreaks of infection, as in Minneapolis, MN and Montgomery, AL. These have the potential to expand into wider outbreaks. And since death is a lagging indicator of infection, it is too early to conclude that the economy is safely reopening without a resurgence of the disease. Be careful and stay safe this holiday.


Living Dangerously (part 3)

May 17, 2020

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Although total deaths from the coronavirus continue to climb, the rate of increase for the United States as a whole continues to fall. This week’s addition of 10,239 deaths represented a percentage increase of 13%, compared to a 19% increase the week before and a 23% increase the week before that. A month ago, for the week ending on April 18, the weekly increase was 90%.

The Institute for Health Metrics and Evaluation continues to project a gradual decline in deaths over the summer. However, it has once again raised its projection of total deaths from 134,475 to 147,040 by August 4, because mortality is not declining quite as fast as previously projected.

A comparison of state mortality data reveals an interesting pattern. The list of the ten states with the highest total deaths has not changed very much. It now includes New York, New Jersey, Massachusetts, Michigan, Pennsylvania, Illinois, Connecticut, California, Louisiana and Florida. The list was similar a month ago, except that it included Washington and Georgia instead of Pennsylvania and Connecticut.

However, the states with the highest weekly percentage increase in deaths are a completely different group. They include Iowa (37%), New Mexico (36%), New Hampshire (31%), Delaware (29%), South Dakota (29%), Arizona (28%), Nebraska (28%), Minnesota (25%), Missouri (25%), and Texas (tied with Alabama at 24%). This is clear evidence that the epidemic is spreading beyond the coastal cities and posing a greater threat to the interior and more rural regions of the country. Those states need to proceed with caution as they try to promote economic recovery without generating a new spike in mortality.


Living Dangerously (part 2)

May 5, 2020

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Two days ago, I reported that the Institute for Health Metrics and Evaluation at the University of Washington had revised its projection of the ultimate US death toll for this wave of covid-19 from 67,641 to 72,433. Given the number of deaths that had occurred already and the current rate of increase—about 1,700 a day in the preceding week—I didn’t see how that projection could stand up. IHME acknowledged that its model did not yet include increased interactions due to the easing of restrictions on public activity.

Yesterday, the Institute released a more sophisticated model that included greater attention to the mobility of populations as well as some other variables. The result is a dramatic increase in the projected death toll, to 134,475 deaths by August 4. As usual, there is a large margin of error, resulting in a range from 95,092 to 242,890. A death toll of 134,475 would far exceed that of any other country. It is about sixteen times the projection for Germany, although the United States has only four times the population of Germany.

The Institute said that its revision upward “is primarily due to longer peaks and slower declines for locations that have passed their peaks.” In addition, “for a subset of states, the easing of social distancing policies has begun and mobility patterns are on the rise.” Those states include Alabama, Florida, Georgia, Idaho, Louisiana, Minnesota, Montana and Texas.

The Institute did not predict an increase of deaths per day, only a slower decline, from about 1,700 now to about 800 by June 1. There is a much more pessimistic document circulating within the federal government that does project such an increase. Deaths per day would start going up in mid-May, reach 3,000 per day by June 1—that’s like having a 9/11 every day—and continue upward from there. The Centers for Disease Control says that this was only a working model that was not finished or ready for release. But apparently someone is taking seriously the possibility that the relaxation of restrictions will lead to a new surge of exponential growth.

The three scenarios I mentioned remain possible:

  1. The warnings from epidemiologists are exaggerated, and the lifting of restrictions will have little effect on the mortality trend
  2. The lifting of restrictions will raise the infection rate somewhat, but not enough to overwhelm medical systems or increase mortality dramatically
  3. The lifting of restrictions will touch off serious outbreaks with exponential increases in mortality in at least some states

Of the three, #1 looks increasingly unlikely, and the choice now facing the country is between bad and very bad.


Living Dangerously

May 3, 2020

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On a week-to-week basis, the United States as a whole continues to see some decline in new deaths from the coronavirus. The worst increase was during the week beginning April 19, with 18,482 new deaths reported, increasing total mortality by 90%. The following week’s increase was 14,224, increasing total mortality 36%. This past week, we saw 12,527 new deaths, increasing total mortality 23% (from 53,314 to 65,841).

Because mortality is not dropping as fast as expected, the Institute for Health Metrics and Evaluation has increased its total projected mortality from this wave of the virus from 67,641 to 72,433. That means that only 6,592 more deaths would occur, a very low number considering that 12,527 occurred just this week. The institute acknowledges, however, an important limitation of its projection:

Our present modeling framework does not yet capture how the risk for more COVID-19 cases – and potentially deaths – could increase due to increased interaction among individuals. This is particularly true if locations have not fully instituted strong containment strategies like widely available testing and contact tracing.

In other words, the modeling does not yet take into account the rush to re-open the economy. Although the country as a whole has experienced slowing mortality, the trend has been very uneven from state to state. Most of the states that are moving to lift restrictions are doing so sooner than recommended, according to both IHME and CDC guidelines. They are not waiting until new cases in their state have declined for two weeks, or until they have “strong containment strategies like widely available testing and contact tracing.” That suggests three scenarios:

  1. The warnings from epidemiologists are exaggerated, and the lifting of restrictions will have little effect on the mortality trend
  2. The lifting of restrictions will raise the infection rate somewhat, but not enough to overwhelm medical systems or increase mortality dramatically
  3. The lifting of restrictions will touch off serious outbreaks with exponential increases in mortality in at least some states

I don’t pretend to know which of these will occur. We do know that just a few weeks of careful preparation and prudent restraint can make a big difference when dealing with something that moves as quickly as an infectious disease. We should find out very soon which states are doing the right thing.

Updated


Ready or Not, Here We Come

April 26, 2020

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As of this morning, the official death toll from covid-19 in the United States stood at 53,314, an increase of 14,224 in the past week. However, the rate of increase slowed to 36%, compared to 90% the previous week and 142% the week before that.

Passing the peak

This week the Institute for Health Metrics and Evaluation reported its latest estimates of peak mortality for countries and states. For the US as a whole, deaths are thought to have peaked on April 15 at over 2,600 a day. That should now fall pretty quickly, but additional deaths are projected to bring the total deaths to 67,641 by the time this wave of the virus peters out in August. Such projections have a large margin of error, and so total deaths could reach as high as 123,157.

A number of individual states have not yet reached their peak daily mortality, but are expected to by the end of May. These include Arkansas, Georgia, Iowa, Kansas, Kentucky, Montana, Nebraska, North Dakota, Rhode Island, South Dakota, Vermont and Wyoming. Most of these states are farther inland than the coastal cities which experienced the epidemic first. All of them except Rhode Island are red states, which may also have been slower to issue stay-at-home orders. Where the mortality has been greatest, the restrictions on public activity are credited with bending the exponential growth curve downward.

When to reopen?

The IHME also suggested dates on which the states could safely lift their restrictions and let people go back to work. The assumption is that if states would keep their restrictions in place until these dates, the rate of infection would then be very low. States could theoretically manage the remaining infections with testing and quarantines, avoiding a serious resurgence of cases and deaths.

Here are the suggested dates, by week:

May 4-10: Montana, West Virginia, Arkansas, Hawaii, Vermont

May 11-17: Idaho, North Carolina, Ohio, New Hampshire, Maine

May 18-24: California, Nevada, New Mexico, Louisiana, Alabama, Tennessee, Illinois, Indiana, Michigan, Wisconsin, Delaware

May 25-31: Washington, Oregon, Wyoming, Colorado, Minnesota, Mississippi, Pennsylvania, New Jersey, New York

June 1-7: Maryland, Virginia

June 8 or later: Arizona, Utah, Texas, Oklahoma, Nebraska, Kansas, North Dakota, South Dakota, Arkansas, Missouri, Iowa, Kentucky, Florida, Georgia, South Carolina, Massachusetts, Rhode Island, Connecticut

The dates reflect both how many cases states have had, but also when they had them. Although the states with the earliest reopening dates have had low mortality, the states with the latest reopening dates are not, for the most part, the states with the highest mortality. Of the ten states with the highest covid-19 death rates per 100,000 population, only three—Massachusetts, Rhode Island and Connecticut—have reopening dates this late. But of the states whose death rates have not yet peaked, all except two—Montana and Wyoming—have the latest reopening dates. That means that some of the states with the highest mortality, especially New York and New Jersey, can reopen before states with relatively low mortality, such as Utah and South Dakota. That will make the later reopening dates a tough sell in many states.

The suggested reopening dates also come with important conditions. They work only if restrictions remain in place up to the reopening date, and they assume that the state is then ready to implement containment strategies including “widely available testing, contact tracing and case-based isolation, restrictions on mass gatherings.” Otherwise surges in cases can occur, even in places that have not experienced them already.

States that are not prepared to do these things will be strongly tempted to try and reopen anyway. Why accept the real hardships of economic recession, with the national unemployment rate already around 16% and climbing, in order to avoid a spike in mortality that is only a mathematical projection? A case in point is Georgia, which has seen only 9 deaths per 100,000 population (a little less than one death per 10,000). And yet epidemiologists do not see it as a good candidate for reopening, since its death rate has not yet peaked and its testing rate is among the lowest in the nation.

The fact that most of the late-peaking states recommended for late openings are red states adds a political component to the mix. If the climate-change debate is any indication, most Republicans would rather risk future catastrophic change than disrupt the existing economy. It should be no surprise that “the easing will not be universal and is cleaved largely along party lines, with some Republican governors moving to reopen key sectors and Democrats moving more slowly” (The Washington Post).

So here we come, ready or not. Some states will throw caution to the winds and forge ahead recklessly. Others may be too cautious and hurt more people than they help. That is where the national mismanagement of the crisis from the beginning has left us. We can only hope that we manage the recovery from this wave of the virus better than we managed the initial spread. And commit to being better prepared for the next one.