Experts say US coronavirus death count is flawed, but close

New York | The US is hitting a tragic milestone: 100,000 dead from the coronavirus. But is that number right?

The accuracy of US coronavirus death count has been both a scientific and political issue. Some conservatives have suggested coronavirus deaths were being over-counted.

Meanwhile, some researchers say the toll is far more likely to be higher than the count.

Here's a look at how deaths are being counted in the US:

The numbers

There is no US coronavirus death count that is both current and complete.

The most recent death data is gathered through searches of preliminary reports doctors send to state and local health departments. Those numbers appear on different websites, including those of government agencies and some news organisations. One widely followed site is maintained by Johns Hopkins University researchers.

But those quick daily tallies ebb and flow for reasons unrelated to when deaths happen. For example, there are fewer reported deaths on weekends, when staffing is lower and fewer people are filing reports.

Still, they are reasonably accurate, said Robert Anderson of the Centres for Disease Control and Prevention.

Why it's complicated

Many people who died of coronavirus were older and already fragile, weakened by heart disease or some other malady. So ascribing a single cause can be challenging.

Experts believe the coronavirus has played an unrecognised role in many deaths - especially soon after the virus arrived in the US. That's in part because testing might not have been available, or because the virus was not thought to be spreading in an area.

"In the beginning of any epidemic, where physicians and health-care workers have less experience with a disease, they're more likely to miss it or misdiagnose it as something else" said Anderson, who oversees the CDC's death statistics work.

Over time, reporting improves, he said.

An evolving count

For months, most states reported only lab-confirmed cases and deaths, though many places didn't have enough accurate tests available to confirm every one.

Last month, the CDC told states to include probable COVID-19 cases in their reports to the agency. Probable coronavirus deaths don't have positive test results but in which other evidence - like the symptoms and course of their disease, and exposure to infected people - points to the infection. Currently, 28 states count only lab-confirmed deaths, while 22 others include probable coronavirus cases, too.

CDC officials say they do not know what percentage of reported deaths are lab-confirmed and what percentage are probable.

Death certificates

Death certificates are the best source of mortality data, because a doctor or medical examiner reviews a deaths - and may even perform an autopsy before assigning a cause. But it can take a month or more for all the death certificates for a given week to make their way to the CDC.

Anderson said his agency is looking both at death certificates that cite coronavirus and looking for deaths that were indirectly caused by the pandemic.

Last month, the CDC said the US has seen at least 66,000 more deaths than usual at that point of the year. The new coronavirus was reported as a cause in about half the excess deaths. But Anderson said it's likely the virus was a factor in many other deaths too.

For example, a death certificate might name pneumonia or other coronavirus complications without mentioning the virus.

"I think there is ample evidence to suggest we are missing some," Anderson said.

AP

AAP