A big shift to health savings accounts could be a huge blow to consumer finances if current HSA contribution patterns continue.

Analysts at Vimo Inc., Mountain View, Calif., a firm that supports use of high-deductible health insurance and HSAs, have given that warning in an analysis of HSA balance data.

The analysts note that only about 20% of members of HSA-compatible plans are actually setting up HSAs, and that the average HSA balance appears to be less than 50% of the average deductible for single HSA coverage.

Meanwhile, private health insurance spending is a form of cash flow that could be viewed as a capitalized asset with a value of about $14 trillion, or about 87% of the value of the U.S. stock market,

If 27% of the U.S. private health insurance market shifts to HSA-compatible, high-deductible plans by 2010, and average HSA asset balances remain low, that could be the equivalent of a 60% cut in the value of the affected employees’ health coverage, and a 5% cut in those employees’ overall compensation, the Vimo analysts estimate.

“The possibility of a significant wealth reduction on such a scale should be grabbing major headlines,” the analysts write. “How, for example, might people react to a 20% or 30% decrease in their equity holdings or home values?”

Consumers, employers and the companies in the HSA market all have to work together to avoid that outcome by increasing HSA funding levels, the analysts write.