COLUMBIA, Mo. -- Data shows nearly 90,000 children and close to 23,000 adults were dropped from Missouri's Medicaid health care program in the past year, prompting a state Democratic leader to call for an investigation.

House Minority Leader Crystal Quade on Sunday publicly released a letter she wrote to Republican House Speaker Elijah Haahr days earlier asking him to launch an investigation of the recent enrollment drop.

"As parents, you and I can both appreciate how wrenching it must be for a mother or father to know their child needs medical attention and to learn they may not be able to get the care they need," Quade wrote to Haahr, who has four children.

In an interview with The Associated Press on Monday, Quade cited concerns about unexpected medical bills that could force people to choose between paying a bill that should be covered by Medicaid or taking a hit to their credit.

She also warned about the implications for parents trying to vaccinate their children before school but suddenly finding they're no longer covered.

Haahr did not immediately comment Monday.

Medicaid is a federal government program that, in Missouri, provides health insurance for children, pregnant women, people with disabilities and other vulnerable, low-income communities.

Quade wrote the drop doesn't appear to be caused by an improving economy. If that were the case, Quade said Missouri would have also seen a similar decline in the number of people receiving food stamps and other government aid.

The Department of Social Services, which oversees Medicaid, did not immediately return a request for comment Monday.