Many hospitals lost both money and patients in 2009, according to Michigan Health Market Review.
In 2009, Detroit hospitals lost $58 million, with the biggest losses at Henry Ford, St. John, and Trinity Health Systems.
Allan Baumgarten publishes the review.
He says the hospitals lost the money on their investments in the stock market, rather than patient care.
"And when the market crashed at the end of 2008, that had a really harmful effect on several of these hospitals."
Baumgarten thinks hospitals will show a profit in 2010 and this year because the stock market has recovered.
All is not well in other areas, however.
Fewer patients are using Michigan hospitals. That"s because many people lost their health insurance -- or their employers switched them to high-deductible health insurance plans.
Baumbarten says high-deductible plans cut down on surgeries for conditions that are not life-threatening.
"If the doctor says, 'I'd like you to have this scoping procedure on your knee, it will improve your golf game,' a couple years ago, somebody might have said, 'well, it will only cost me $100 out-of-pocket, so why not?' But if I've got a high-deductible health plan, this procedure might cost me $2,000 out-of-pocket."
Revenue at thirty-three other hospitals across the state also dropped in 2009, led by losses at the University of Michigan and several other health systems which lost large amounts in their stock market portfolios.
The report also includes enrollment figures for the state's HMOs.
Commercial enrollment declined in 2009, because many employers shifted their plans to PPOs or higher-deductible plans.
However, overall enrollment in HMOs in Michigan rose 3.7%, because more people became eligible for Medicaid. Almost all Medicaid patients are in HMOs rather than other kinds of health insurance plans.
Baumgarten says the state's Medicaid HMO plans will continue to gain membership as provisions of the national health insurance reform act take effect.
The act allows people whose income is 133% of the poverty line to enroll in Medicaid.