Without sustained improvement in the test supply chain and lab results, Michigan faces significant roadblocks to loosening its economic lockdown.

Under more generous criteria announced by the White House in a phased plan last week, Michigan still must satisfy threshold criteria for testing (and in areas such as hospital capacity and illnesses in the community).

For testing, the federal guidelines require one of two conditions be met:

That the number of confirmed COVID-19 cases decline over a 14-day period, or

The percentage of people who test positive must fall for 14 days — provided the number of tests given remains flat or increases over that period

Michigan, which had administered nearly 114,000 coronavirus diagnostic tests as of Sunday, has yet to meet either measure.

Daily confirmed cases of the coronavirus have mostly fallen over the past two weeks, but not consistently. And while the percentage of people who test positive has mostly dropped, the number of tests administered have dropped at times, too, according to state data.

Public health organizations and researchers set their own yardsticks for what level of testing is sufficient.

The World Health Organization contends that for a government to reopen, the percentage of people testing positive for COVID-19 should be between 3 percent and 12 percent.

Michigan is not close.

Over the past two weeks on average, nearly 30 percent of Michiganders tested received positive results, MDHHS data show. For three days now, the proportion of tests with positive results has dropped below 21 percent. Nationally, about 19 percent of coronavirus tests are positive, according to the COVID Tracking Project.

A high percentage of positive tests suggests not enough people are being tested. Michigan is a good example of that. In the initial weeks of the pandemic, Michigan followed strict guidelines set by the U.S. Centers for Disease Control and Prevention, limiting testing to people with serious symptoms because there were not enough tests to go around.

That meant those with mild symptoms or none at all were rarely tested. As more people are tested, especially those who have mild or no symptoms, this figure should fall.

A team of researchers at Harvard recently announced its own testing measure.

The Harvard team said the United States needs to triple its level of testing to 152 tests per 100,000 people by May 15 to safely reopen the country. Currently in Michigan, testing levels are at 45 per 100,000, based on a seven-day rolling average.

“We have a long way to go before vaccines are available, and we need to keep this transmission of COVID-19 in check or we’ll be back to where we were,” said Dr. Joseph Eisenberg, chair of the epidemiology department at the University of Michigan.

He, too, said Michigan needs a sustained, downward slope of cases and deaths. As social distancing rules relax, adequate levels of testing will help policymakers identify who can return to the workplace and with longer-term pandemic surveillance.