When he took office, he said, carriers complained of having to send in every bill they paid, telling him: "It's costing us a whole pile of money to submit. What are you doing with it?"

Mr. Emrick said there were some high estimates that since 1999 it has cost insurers in the state $10 million to provide the data. He said after he proposed the regulatory change to eliminate the requirement there were no requests for a hearing.

The move was warmly received by the insurance industry. According to the American Insurance Association, the requirement led to increased premiums for consumers as insurers had to outsource the administrative operations involved in gathering and processing the information.

"Kentucky's experience is the clearest example yet of how states choose to require insurer reporting of data simply because they can, with no clear benefit in mind," said Raymond G. Farmer, AIA assistant vice president for the Southeast Region.

Mr. Farmer noted that Kentucky appears to be the exception rather than the rule, noting that several other states are considering medical claims data reporting requirements without also crafting a clear plan as to how that data would be used by regulators.

"Unfortunately, such misguided regulation simply increases costs without producing any demonstrable benefit for the system as a whole," Mr. Farmer said.