FRIDAY, May 8, 2020 (HealthDay News) -- Among detected cases of COVID-19 in the United States, 1.3% of patients will die from the illness, according to a new calculation. But that rate could increase if current precautions and health care capacities change, the study's author said.
The 1.3% rate calculation is based on cumulative deaths and detected cases across the United States, but it does not account for undetected cases, where a person is infected but shows few or no symptoms, according to researcher Anirban Basu.
If those cases were added into the equation, the overall death rate might drop closer to 1%, Basu said.
He directs the department of pharmacy at the University of Washington in Seattle.
Basu stressed that the current estimates apply "under the assumption that the current supply [as of April 20] of health care services, including hospital beds, ventilators, and access to health care providers, would continue in the future." Declines in the availability of health care services could increase COVID-19 death rates.
Most crucially, social distancing and other preventive measures will help keep the U.S. COVID-19 death rate down, Basu said. Accordingly, recent White House COVID-19 Taskforce projections of 100,000 to 200,000 deaths this year from COVID-19 are made with assumptions about the effectiveness of measures that are currently in place, he said.
Many states are already moving to relax restrictions on "shelter in place" rules, with businesses, beaches and parks reopening.
The estimated COVID-19 death rate of 1.3% is still much higher than the U.S. death rate for seasonal flu for 2018-2019, which was just 0.1% of cases, according to the U.S. Centers for Disease Control and Prevention.
On the other hand, the new estimate is much lower than prior death rate calculations. For example, China's COVID-19 death rate was initially reported to be 5.6%, falling to 3.8% by Feb. 20. But that could be due to timing: As in China, U.S. rates were much higher in the early stages of the pandemic, Basu noted.
The new study's findings are based on 40,835 confirmed COVID-19 cases and 1,620 confirmed deaths in 116 counties across 33 states through April 20. Death rates varied widely across locales, with some counties recording a death rate of just 0.5% while others went as high as 3.6%.
According to Basu, determining the COVID-19 death rate is crucial in the fight against the coronavirus pandemic.
"When used with other estimating approaches, our model and our estimates can help disease and policy modelers to obtain more accurate predictions for the epidemiology of the disease and the impact of alternative policy levers to contain this pandemic," he wrote in the report published online May 7 in Health Affairs.
"The CDC reports a significant variation in fatality rates by age groups. Further work is required on this front," Basu added in a journal news release.
The estimate of the U.S. COVID-19 death rate is "not outside the ballpark" of estimated rates available from other countries, but lower, he concluded.
The U.S. Centers for Disease Control and Prevention has more on COVID-19.