YARMOUTH — A study released by a conservative advocacy group has shown wide disparities in what Maine providers charge for the same medical procedures.

The Maine Heritage Policy Center’s study found significant differences in charges for common procedures. A blood test for electrolytes ranged from $33 to $111. A knee replacement ranged from around $27,000 to $50,000.

The report compares prices at 33 hospitals across the state.

An analyst at the nonprofit says patients are often unaware of price differences and unmotivated to seek affordable care. The center’s CEO says the solution is to provide incentives to consumers to compare costs and shop around for the best deal.

But an analyst with the Maine Center for Economic Policy says competition in Maine’s small health care market wouldn’t be enough to drive prices down.