DALLAS -- More than 400 doctors are quitting Aetna U.S. Healthcare in Dallas, alleging the managed care company wasn't providing enough information for them to adequately manage their risk.

The move by members of the Genesis Physicians Practice Assn. has the potential of displacing some 30,000 patients enrolled in Aetna U.S. Healthcare plans in the Dallas area.

"When we entered the contract, it was understood that we would take our own risk," explained Dr. Theresa Shouse, vice chairwoman of Genesis, which is affiliated with the Presbyterian Health Care System in Dallas.

In order to do that, the physician group needed data from Aetna U.S. Healthcare on enrollment, capitation rates and utilization management, among other things, she said.

But "when Aetna merged with U.S. Healthcare, they merged their computers, and their information return went to nothing," Dr. Shouse complained.

"Most of the information was nine to 12 months old, and the data was inaccurate and incomplete," she said.

"I don't believe a physician group should be at risk without the ability to manage that risk," Dr. Shouse asserted.

Not everyone in the community, however, thinks the dispute centers on information-sharing. "We think it all comes down to money," said Marianne Fazen, president of the Dallas-Fort Worth Business Group on Health.

In July, the physician group charged Aetna U.S. Healthcare with breach of contract, giving the HMO 90 days' notice to reassign affected patients to other Aetna doctors. The notice period expired last week.

In response to the doctors' demand for more updated and accurate information, the insurer invoked the "all products" provision of its physician contracts, which require doctors who refuse to participate in its HMO to be denied access to patients in all other Aetna plans, including its preferred provider organization and point-of-service plans.

Aetna officials in Dallas referred Business Insurance inquiries to its Blue Bell, Pa., public relations office, which did not return calls.

Employers affected by the decision declined to comment for publication. Ms. Fazen did acknowledge that "it's causing some disruption, but Aetna's been telling employees they will find them new doctors" in Aetna plans.

If an employee would rather change health plans to keep a doctor, it could take anywhere from weeks to months for that employee to change HMOs, depending on how a benefit plan is administered. Those with only a yearly enrollment opportunity would have the most difficulty changing plans.

A consultant who works with many large Dallas-area companies said several of them have decided to contract with other

HMOs that offer access to Genesis physicians to allow employees to keep their doctors.

"One of the most disruptive things that can happen in an employee benefit plan is a change in provider relationships," observed Michael Winter, a consultant with Watson Wyatt Worldwide in Dallas. Additionally, Mr. Winter said, it's the heavy users, those undergoing continuous care, who will complain the most.

"The 400 doctors cut will impact a fair percentage of the network, even though Aetna's network grew 25% last year," he said.

Indeed, many members of the Dallas health care community say those enrolled in Aetna U.S. Healthcare who were using any of the 400 Genesis doctors as their primary care physicians will have a hard time finding replacements.

"All the PCPs are very full and very busy, and many of those on the new Aetna list are not taking new patients," said Dr. Shouse. "So when these people get reassigned, where will they go?"

Ms. Fazen, however, disagrees. "Certain physicians who have depended on Aetna for a large part of their business may not be able to hold out very long," she said.

Mr. Winter said he spoke with one human resources manager last week who said that instead of waiting for employee complaints, she would add another plan that included the Genesis doctor group.

Genesis has contracts with more than 80 other managed care companies, including Philadelphia-based CIGNA Corp. and Richardson, Texas-based Blue Cross & Blue Shield of Texas, according to Dr. Shouse.

The Dallas County Medical Society and the Texas Medical Assn. issued a joint statement announcing its disappointment with Aetna U.S. Healthcare and its support of the Genesis move.

"It seems Aetna will not relent on our doctors' modest request to correct operational problems that have made it impossible to manage their patients' care. Remember, this is an HMO that cannot, on a daily basis, tell its contracting doctors where or who its patients are, what kind of medications they are taking, or even what hospital they are in," said a joint statement from Dr. Robert T. Gunby Jr., president of the Dallas County Medical Society, and Dr. John P. Howe III, president of the Texas Medical Assn. in Austin.

"There is still time for Aetna to do the right thing and suspend this absurd business practice that evidently comes from Blue Bell, Pa., and not from Dallas, Texas," the statement continued. "This is an easy, simple decision, and it would drastically reduce the number of patients affected by their corporate philosophy. Unfortunately, it appears there is no softening in Aetna's hard line. Our physicians have been steadfast in their insistence that they should be able to manage care and not just have to manage costs."

Aetna U.S. Healthcare has been renegotiating its provider contracts nationwide since the insurer merged with the HMO in 1996.