Oregon has now performed the second fewest coronavirus tests per capita in America, national testing statistics show.
Oregon ranked fifth lowest as of last Friday but was leapfrogged by a surge in testing in Missouri, Arizona and Colorado, three of the four states that had trailed Oregon, according to an analysis by The Oregonian/OregonLive.
Now, only Idaho has performed fewer tests per capita.
Testing rates in a vacuum do not capture Oregon’s relative success nationally in slowing coronavirus, however.
Oregon has the sixth lowest positive test rate nationally -- that is, finding an infection among people tested. The 3.2% rate indicates that while more testing would identify more infections, it would not likely detect an unexpectedly high number of infections.
In fact, as Oregon increased testing in the past month the likelihood of finding an infection dropped from about one in 20 people tested to now about one in 33 cumulatively since the pandemic began.
In the past week, it’s been about one in 50, according to Johns Hopkins University.
The newsroom regularly analyzes data from the COVID Tracking Project, which collects testing figures from each state. It’s the same dataset used by Johns Hopkins University, which, as Willamette Week first reported, has an online chart showing Oregon with the second lowest testing per capita.
Oregon’s new place in the rankings in the past week happened because Missouri, Arizona and Colorado all reported far more tests. Colorado reported new tests for about 34,000 people between May 28 and Thursday; Arizona reported about 47,000 new tests; and Missouri reported about 48,000 new tests.
Oregon’s testing total increased by only about 20,000 during that timeframe.
About 33 of every 1,000 Oregonians have been tested for a coronavirus infection, compared to 34 for Arizona and Colorado, and 35 for Missouri.
Idaho has tested about 28 people per 1,000 residents. Rhode Island leads the nation at about 157 tests per 1,000 people.
Oregon’s ranking compared to its closest testing peers shows just how well the state is doing, comparatively.
Missouri and Idaho have each found about twice the rate of infections as Oregon among residents tested; Arizona’s rate is nearly three times higher; and Colorado’s positive test rate is more than four times higher.
But Oregon’s per capita testing rate also shows how many infections have likely gone unidentified. New Mexico, for example, has tested a far higher share of its residents (about 102 per 1,000) and among those has found a similarly low rate of positive tests (about one in 25).
If Oregon matched New Mexico’s rate of tests among residents, nearly 425,000 Oregonians would have been tested by now.
Assuming the same rate of positive tests, Oregon would have identified about 13,600 total infections – roughly three times what officials have found (but still less than the 20,200 actual infections estimated in modeling through May 22).
The Oregon Health Authority on Friday did not immediately respond to a request for comment.
The statistics collected by the COVID Tracking Project – a website that compiles state testing data – are among the most reliable in the country. But they have some caveats.
For example, the website adds positives and negatives to arrive at state testing totals, and protocols vary by state.
The COVID Tracking Project slightly inflates Oregon’s testing count by adding positives and negatives together. That’s because Oregon reports not only confirmed positive tests but also presumed positives for people who may not have been tested.
As of Thursday, more than 139,000 Oregonians had been tested, with 4,350 confirmed infections and 124 presumed infections.
More Oregonians could be tested each week. The state has enough supplies and resources to test nearly 38,000 people weekly, officials have said, but the actual number of tests is about half of that.
Federal and state officials set a goal that Oregon would test 80,000 people a month in May and June – a figure that would have tied for the lowest among all 50 states, on a per capita basis.
Oregon didn’t hit that target. The state reported tests in May for only about 73,000 residents.
-- Brad Schmidt; bschmidt@oregonian.com; 503-294-7628; @_brad_schmidt
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