A Sunday update of a prominent COVID-19 forecasting model suggests that fewer lives will be lost during the first wave of the coronavirus outbreak than previously thought.
The University of Washington’s Institute for Health Metrics and Evaluation (IHME) now predicts that 81,766 people will die of COVID-19 in the U.S. through early August. When the model was last updated, on April 2, it predicted 11,765 deaths more deaths, for a total of 93,531.
The model, which has been cited by the White House, relies on numbers from China, Italy, Spain, and areas around the U.S. The change in prediction is due to “a massive infusion of new data,” IHME director Dr. Christopher Murray said in a press release.
According to its website, the IHME model was developed to “provide hospitals, health-care workers, policymakers, and the public with crucial information about what demands COVID-19 may place on hospital capacity and resources, so that they could begin to plan.” The model’s latest update includes several important changes related to that planning. Many fewer hospital beds will be needed at peak than previously anticipated, according to the new projections. The April 5 update predicts the need for 140,823 total hospital beds and 29,210 ICU beds at the peak of the outbreak. Those numbers are down 121,269 and 10,517, respectively.
The model also revised downward the prediction for the number of ventilators needed at the height of the outbreak. It now predicts the need for 18,992 ventilators, down from 31,782.
One thing that didn’t change between the April 2 and April 5 models is the projected date of the outbreak’s peak. The model still predicts an April 16 apex for the daily COVID-19 death rate. Hospital use is expected to peak on April 15.
Among the information that led to the April 5 changes is data from states showing lower ratios of hospital admissions to deaths. That results in “predicted peak hospital resource use — total beds, ICU beds, and invasive ventilators — that is lower than previously estimated,” according to the IHME’s explanation of the revised predictions.
The IHME model is based on several key assumptions about social distancing in the U.S. It assumes all states will lock down — closing schools, telling residents to stay at home, closing nonessential businesses — and that “implementation and adherence to these measures is complete.” Crucially, it also assumes the continuation of social distancing until early August, well beyond the April 30 guidelines currently set forth by the White House.
Though the update of the model appears to be good news, at least for now, Murray counseled caution. “If social-distancing measures are relaxed or not implemented, the U.S. will see greater death tolls, the death peak will be later, the burden on hospitals will be much greater, and the economic costs will continue to grow,” he said.