President Trump gave the United States a pat on the back on this week, saying the nation had done more coronavirus testing than South Korea, a country widely seen as a model in its management of the pandemic. But his comparison was misleading.

“Just reported that the United States has done far more ‘testing’ than any other nation, by far!” Trump said in a tweet Wednesday morning. “In fact, over an eight day span, the United States now does more testing than what South Korea (which has been a very successful tester) does over an eight week span. Great job!”

The United States, which now has the largest outbreak in the world, was very late to the testing game. But the country has indeed scaled up from extremely low levels. It had done 540,718 tests as of Friday, according to the COVID Tracking Project.

But the U.S. population is more than six times South Korea’s. As of Friday, South Korea had tested 376,961 people, or 0.7 percent of its 2018 population of 51.6 million.

In comparison, the United States has still tested only about 0.2 percent of its population, based on these figures.

The fact that the United States lags is due “to a lot of things, including shortages of not only tests but the stuff to purify RNA and even swabs to collect samples,” said William Hanage, a professor of epidemiology at Harvard.

Hanage added in an email that when it comes to the United States tests that have been conducted, “a huge proportion of the few tests that have been run have been from N.Y. They alone are over 100k. What this means is that local testing rates are even lower elsewhere.”

The United States is also ahead of South Korea in a category it would rather not be leading: total deaths. As of Friday, 1,246 people in the United States had died of the virus, according to the Centers for Disease Control and Prevention (the Johns Hopkins tracker puts that figure even higher), while in South Korea as of Friday, 139 people had died. Not that that’s a fair comparison either — death rates in the two countries are actually quite similar at 1.5 percent of cases, at least for now.

As this shows, making comparisons between different countries is fraught with inconsistencies and holes. The world has, thus far, shown a highly varied response to the coronavirus threat.

“It’s not just testing as a proportion of the population, it’s testing that’s employed strategically to diagnose, so that contact tracing can be done to get people isolated, and contacts quarantined in areas that were hard-hit,” said Tara Smith, an expert on infectious diseases at Kent State University in Ohio.

For an example of the wildly different approaches out there, consider that Japan has hospitalized 95.7 percent of people who tested positive, but it has a very low testing rate. It has tested 0.02 percent of its population. (The United States has hospitalized between 20.7 percent and 31.4 percent of people who test positive, based on a study of 2,449 cases in the country by the CDC.)

And both testing and hospitalization numbers are likely to be made up of people who came in for testing or complaining of symptoms. But many people might die of the coronavirus without ever seeking or receiving medical care.

“Some [countries] are testing postmortem and some aren’t, so some are catching those who die of pneumonia but weren’t tested until death, and some are likely missing those deaths from their counts,” Smith said.

In a survey of a dozen countries with significant outbreaks, The Washington Post found that not all make testing information available. But of those that do, Norway had the highest rate of testing that we could identify. The sparsely populated nation administered 78,036 tests, accounting for 1.5 percent of the population, as of Friday.

Other countries also greatly lead the United States

Take Germany, where the current death rate from the disease remains remarkably low, at just half a percent. The reason isn’t clear, but one factor may be that the country has been testing heavily.

Germany has tested 483,295 people so far, according to the country’s Robert Koch Institute, an even higher total number than South Korea. That means that so far Germany has tested well over half a percent of its population, considerably more than the United States has done. And Germany’s numbers are set to increase rapidly from there.

The total number of tests in the country each week is now between 300,000 and 500,000, said health minister Jens Spahn. “Worldwide that should be the largest number of tests in any country, in absolute and relative numbers,” Spahn said.

If mortality is the ultimate measure, then the U.S. deaths as a percentage of total identified cases are three times higher than Norway’s and Germany’s. Only 16 people have thus far died of the virus in Norway and only 198 in Germany.

But the highest death rates so far have been Italy’s 9.2 percent and Spain’s 7.6 percent, based on current figures on total cases and total deaths — sobering statistics given that many people think the U.S. curve might be steeper.

Loveday Morris in Germany contributed to this report.