The Federal Trade Commission said yesterday it has warned the American Society of Internal Medicine that its proposed "relative value guide" for physician services may violate antitrust laws.

RVGs are one of many new tools designed to help health care buyers make cost comparisons. The guides provide estimates of the relative value of various medical services.

ASIM wants to develop an RVG of internists' services that internists and large benefit providers, such as private firms and government agencies, could use as a guide in developing cost reimbursement plans, the FTC said.

The professional association believes that certain services provided by internists are undervalued compared with some other medical services. ASIM hopes the guides would remedy "an alleged disparity in reimbursement for 'cognitive' services, such as diagnosis and preventive education, and 'procedural' services such as surgery, electrocardiograms and other technology-intensive services," the FTC said.

Internists primarily deliver "cognitive" services, which currently cost less. The association's RVG would increase the relative value of cognitive services and lower the relative value of procedural services, according to a proposal submitted to the FTC.

ASIM requested an FTC advisory opinion on its proposal, arguing that it "would reduce health care costs and encourage physicians to spend more time in personalized aspects of care," the agency said.

The commission issued an opinion stating there is a "substantial danger" that the proposed RVG "would lead to a combination or conspiracy that unreasonably restrains competition" in violation of federal antitrust law.

The FTC said the RVG plan "would tamper with market pricing structures, pose a danger of higher prices with respect to some medical services and have other possible anticompetitive effects."

The opinion is limited to the specific RVG plan proposed by ASIM, the agency said.