Gov. Gretchen Whitmer claims in a legal brief now before the Michigan Supreme Court that COVID-19 killed more people in Michigan during the month of April than heart disease and cancer combined. A hearing in the case is scheduled for Sept. 2.

The claim is not accurate. It was based on figures published by a state website that supported Whitmer’s claim at that time. The site publishes the total deaths right at the start of each month, though the reported figure is considered preliminary. Experience has shown that the actual number may be much larger, which may not be known until months later.

Whitmer’s court brief apparently cited the May 5 version of this state website. The site then indicated there were 10,330 deaths in Michigan from all causes in April, including 2,366 linked to heart disease or cancer, and 2,386 linked to COVID-19.

But by August, the updated tally for April said Michigan had experienced 13,011 deaths from all causes, of which 3,277 were related to heart disease or cancer, and 3,232 were linked to COVID-19.

Michigan Capitol Confidential reported July 9 the total number of deaths in Michigan during June, citing the same state website Whitmer’s legal team mentioned in its Supreme Court brief. The website then reported a total of 7,107 deaths in June, but after updates, the data now indicates there were a total of 8,195 deaths in Michigan that month.

This state website does tell users that the number of reported deaths may change: “Deaths reported to the Michigan Vital Records office may be delayed by 7 days. Verifying the cause of death, and processing the records from adminstrative [sic] records may further delay the reports of deaths for statistical purposes.”

But the site does not inform users that the adjustments can be quite substantial. For example, the initial figure posted for all deaths in April underreported the actual number by 75%.

Specifically, on May 1, the website said 7,431 people had died in Michigan during April. Several months later, the number was revised to show 13,011, or an additional 5,580 people — 75% higher.

Currently, the Aug. 3 version of the state’s website indicates that in July, there were a total 3,198 deaths in Michigan from all causes, including 51 related to COVID-19. But a different state website shows there were 214 COVID-19 deaths here in July. These numbers are likely to be much higher when the site is updated again next month.

The Michigan Department of Health and Human Services, which oversees the website, stated that they "publish the data that is available at the time – and note that there are delays in the information being reported to us."

Editor's note: This story was updated with a response from the Michigan Department of Health and Human Services.