Explaining Michigan’s COVID-19 Numbers

Helping you understand what you’re hearing

Dave Hogg

Apr 27, 2020·5 min read

If you’ve been following Michigan’s official COVID-19 counts, you are probably getting confused. Daily death counts are all over the place, and confirmed cases are going up while things are supposed to be getting better. Also, what’s Region Two North?

Hopefully, this article will answer your questions.

Every day at 3 p.m., the state releases a vast amount of data onto its dedicated coronavirus website. Most people only see the daily death count reported on a news site, possibly with the case number attached, but there’s a lot more on the site.

Before we get into all of that, though, let’s discuss the issues you might be having with the two numbers everyone is seeing.

DEATH COUNTS

As I write this on the afternoon of April 26, the state has just announced today’s death count: 41. At first glance, that’s a reason to celebrate — it’s the lowest number since there were 21 deaths reported on March 29.

However, it isn’t that simple. On Saturday, the state announced 189 deaths, meaning the daily total dropped by 78 percent in 24 hours. That probably seems unlikely, and it is. Neither Saturday’s number nor Sunday’s reflect an accurate total of what they are supposed to be measuring — the deaths between 10 a.m. on the previous day and 10 a.m. the day of the announcement.

There are two reasons for this — an admirable one and one that reflects the state of the American health system in 2020.

First, unlike other states and nations, Michigan is trying to capture an accurate total of all its COVID-19 deaths, no matter when or where they occur. Under their current strategy, they add reclassified deaths into the totals on Tuesdays, Thursdays, and Saturdays. That’s why the totals for the last week have looked like this:

• Monday: 77
• Tuesday: 232 (95)
• Wednesday: 113
• Thursday: 164 (55)
• Friday: 108
• Saturday: 189 (58)
• Sunday: 41

Luckily, the state doesn’t put out those numbers without explanation. The figures in parenthesis are the number of reclassified cases each day. So strictly in terms of new deaths, the week went 77, 137, 113, 109, 108, 131, 41 with another 208 where we don’t know the exact date. In total, that’s 924 for an average of 132/day. That’s a little higher than the previous week’s average of 129 but isn’t a reason for concern. Last week, the state didn’t add reclassified deaths to Saturday’s total, saving them for Tuesday and raising this week’s average.

There’s another issue with the daily totals, and you can probably pick it out with a quick look at the list for this week. Monday’s 77 seems too low, and Sunday’s 41 is even more out of place. That’s a regular occurrence; hospitals usually have smaller staffs on the weekend, so deaths aren’t always immediately reported to the state. That results in lower-than-expected numbers on Sundays and Mondays, and after everyone catches up on their paperwork, a significant spike on Tuesdays.

So expect a low number on Sundays and Mondays, followed by a jump up on Tuesdays. The Tuesday numbers are further enhanced by the first of Michigan’s three weekly updates of reclassified deaths.

CASE NUMBERS

After reading the first section, you should have already realized one of the reasons case numbers jump around — the weekend effect. Testing slows down on Saturdays and Sundays, and there are still reporting delays.

However, case numbers are also confusing in another way. Simple logic tells us more people get sick during the growth of a pandemic, while fewer people fall ill as the outbreak begins to decrease.

That’s not the case with COVID-19, however. The crisis snowballed that, with limited supplies, hospitals were only able to test people who already showed signs of being seriously ill. That resulted in low numbers of tests with a very high positive rate.

In the last week, the state has significantly increased its testing rate. The rate of positive tests has declined — Friday’s was down to 13% on 7,291 tests — but the new volume of testing has produced more positive tests overall.

Under the circumstances, that’s a good thing. It was apparent that many cases were going undiagnosed, and the increased testing is allowing the state to start catching them.

OTHER DATA

The state’s COVID-19 site includes more information every day, including cases by estimated onset date, hospitalization numbers, and available medical supplies. That last category covers everything from ICU beds and ventilators to gloves, gowns, and masks.

You need one more piece of the puzzle before you can get full use of the data — Michigan’s Healthcare Coalition Regions.

Many of the tables include eight regional breakdowns and the overall state total, but it isn’t immediately clear how the regions work. Here’s the list you need:

• Region 1: South-central Michigan: a corridor including the counties along US-127 from the Ohio border to Gratiot county. The largest cities are Jackson and Lansing.
• Region 2N: The northern half of Metro Detroit: Oakland, Macomb, and St. Clair counties.
• Region 2S: The southern half of Metro Detroit: Wayne, Monroe, and Washtenaw counties.
• Region 3: The Thumb and the counties on the northern coast of Saginaw Bay.
• Region 5: Southwestern Michigan: the Indiana border north to Allegan and Barry counties. This region includes Kalamazoo and St. Joseph.
• Region 6: Central western Michigan: From Ottawa County to Mason County on the Lake Michigan coast over to an eastern edge running from Ionia County to Clare County. The largest cities are Grand Rapids and Muskegon.
• Region 7: Up North: the rest of the Lower Peninsula, running from Manistee through the Straits of Mackinac and down to Alpena. It includes Grayling, Gaylord, Traverse City, and Mackinaw City.
• Region 8: The Upper Peninsula

No, that list isn’t missing an entry. At some point, a reorganization of the zones resulted in the removal of Region 4.

As you would expect, the U.P. has the fewest cases and, as of April 26, is home to the last five counties without a reported infection: Keweenaw, Ontonagon, Baraga, Iron, and Alger. More than 80 percent of the state’s hospitalized patients are in Regions 2 North and 2 South.

If you want to use numbers to track Michigan’s recovery from the COVID-19 outbreak, there’s a lot to explore. One last word of warning, however. The state website has not released an archive of the hospitalization data, so if you are trying to find trends, your best bet is probably this Google spreadsheet.

Hopefully, this article will give you a greater understanding of the daily data released by the state. I believe it shows Michigan is making progress but has not reached the finish line.