IHME Model Estimates 93,765 U.S. Coronavirus Deaths

The Institute for Health Metrics and Evaluation (IHME) model cited by White House Coronavirus Task Force officials has increased its projections of the number of coronavirus deaths in the United States by August 4 to 93,765.

The projection is based on key assumptions about the implementation of social distancing policies, the IHME said in a statement released on Wednesday:

These estimates assume the strong continuation of statewide social distancing measures in places where they are already enacted, and future adoption within the next seven days in states without them. If such policies are relaxed or not implemented, the US could experience a higher COVID-19 death toll and hospital burden than what our models currently predict.

The model now projects 12,651 more deaths in the United States than it projected five days ago when its first projection of 81,114 coronavirus deaths was announced on March 26. The model’s estimation of coronavirus deaths has increased with every published update. On Monday, March 30, at 6:00 a.m. Pacific Time, the model projected 82,141 coronavirus deaths by August 4. Just 24 hours ago, on Tuesday, March 31, at 6:00 a.m. Pacific Time, the IHME model projected 83,967 coronavirus deaths in the United States by August 4.

Wednesday’s projections represent an increase in estimated coronavirus deaths of 9,798 based on a single day of new data. The model is dynamic, and its projections for the country and individual states are updated every 24 hours at 6 a.m. Pacific Time based on the most recently reported data.

The increase “is primarily driven by increasing death tolls in states that previously had very few COVID-19 deaths. States with more COVID-19 deaths, such as New York and Washington, show far less fluctuation across daily updates. If the number of cumulative COVID-19 deaths rise by state, we expect increasing accuracy for predictions across states, the IHME said in Wednesday’s statement.

The sensitivity of the model’s projections to new data confirms what White House Corona Task Force member Dr. Anthony Fauci has stated about epidemiological modeling of the course of the coronavirus pandemic: “it’s a moving target.”

The IHME statement added:

Today’s estimates show that nationwide, COVID-19 deaths are predicted to peak on April 16, when we predict 2,607 deaths (range of 1,294 to 4,140) in a single day. This projection is higher than our estimates released on March 31, which projected peak US COVID-19 deaths at 2,214 (range of 1,106 to 3,321) on April 15.

April 16 also is now estimated as the peak hospital use date in the US. At this peak date, the US is projected to need 260,342 total hospital beds (38,849 for ICU) and 31,082 ventilators to support COVD-19 patients. This could equate to a projected shortage of 84,671 total hospital beds and 18,905 ICU beds given current COVID-19 trajectories.

The statement also provided these additional details on data updates and how they influenced the model’s new estimates:

• Our COVID-19 death modeling approach involves fitting state-specific curves with CurveFit (see documentation here) wherever there is sufficient data and an average curve for other states. In today’s release, we were able to fit state-specific curves for three additional states: Alabama, Delaware, and Iowa. This resulted in important changes in today’s estimates for these states.
• Notably, fitting on new data released on March 31, the cumulative COVID-19 death estimates for Alabama increased to 7,334 . . .  an estimate that is 6,161 deaths higher than previous estimates.
• 13 other states still use “average curves” for their prediction fits. Our daily projection updates for these states are less stable a day-to-day. This is because uncertainty (the range) is much higher in the absence of more data. These 13 states are Alaska, Hawaii, Maine, Montana, Nebraska, New Hampshire, New Mexico, North Dakota, Rhode Island, South Dakota, Utah, West Virginia, and Wyoming.

An updated estimate of total coronavirus deaths, hospital capacity, and peak days as projected by the IHME model is expected to be released at 6:00 am Thursday, April 2.

The IHME COVID-19 model research project is run by Professor Christopher J. L. Murray of the University of Washington, the director of the IHME. “Funding was provided by the Bill & Melinda Gates Foundation and the State of Washington,” according to the report on the study published on March 30 at MedRxiv.