In most countries, including the United States, guidelines stipulate that any death where COVID-19 is a factor or contributor is counted as a COVID-related death.

But in China, health authorities count only those who died directly from COVID-19, excluding those, like Lu, whose underlying conditions were worsened by the virus, said Zhang Zuo-Feng, an epidemiologist at the University of California, Los Angeles.

“If the deaths could be ascribed to underlying disease, they will always report it as such and will not count it as a COVID-related death, that’s their pattern for many years,” said Jin Dong-yan, a virologist at the University of Hong Kong’s medical school.

That narrower criteria means China’s COVID-19 death toll will always be significantly lower than those of many other nations.