Pharmaceutical companies fail to publicly reveal all of the money and gifts they give to physicians and health care workers - making it hard to know what the money is for.

A new analysis found that records were sketchy and hard to access in two states that require drug companies to publicly disclose payments made to physicians.

Five states and the District of Columbia have enacted so-called sunshine laws that require companies to report how much money they pay doctors and other health care workers as well as in what form and for what purpose. Such payments can range from consulting fees for clinical trials to meals to "detailing" (paying doctors to let drug-marketing reps talk up their drugs during the workday), some of which can raise concerns about conflicts of interest when doctors are prescribing the companies' drugs to patients.

The purpose of the laws is to monitor whether money and gifts influence physicians' decisions when prescribing meds. To determine whether the laws are working, researchers requested data from Minnesota, home of the country's oldest such law, enacted in 1993, and Vermont, which passed its measure in 2002.

The group reports that it was a challenge just to obtain the documents. In Vermont, the state's attorney general is charged with collecting the data and tabulating the results for the public. "We thought it meant the public had access to it," says health services researcher Joseph Ross of the Mount Sinai School of Medicine in New York City, the study's lead researcher. But he says they waited nearly a year to get detailed information from the state for 2002 to 2004, during which 58 companies reported forking over $5.6 million to health care professionals.

Of that sum, the state withheld information on $3.4 million in payments that the companies designated as trade secrets, for which Vermont makes an exception. "What they were doing," Ross says, "is saying that all of their payments were trade secrets ... It's improbable that all of a company's payments were truly proprietary." Moreover, in 75 percent of the reports handed over to the researchers, the companies failed to identify the gift recipients despite a legal requirement to do so, Ross says.

In Minnesota, where the law states that the information should be made publicly available, the researchers had to travel to the state board of pharmacy and photocopy thousands of individual reports at 25 cents per copy. Although 97 percent of the payment reports named the payee, only 15 of 60 companies consistently disclosed payments in each of the three years reviewed. Biotech heavyweight Amgen, for example, reported payments of $4 million in 2003, but none in 2002 or 2004.

For both states, the researchers examined all payments over $100 - the cap on marketing activities recommended by the American Medical Association and a trade group representing the pharmaceutical industry. "It's really hard based on the information we had to determine which payments were appropriate and which were not," Ross says, "because payment descriptions were really vague".

Patients themselves may not want to police doctors, but surveys have found that they expect a doctor's employer to have policies to deal with potential conflicts of interest. "If the information's not transparent to the public or patients," Ross says, "it means the information's not transparent to department chairs or the people who own these practices." Strengthening the laws would require greater enforcement and a simpler format for making the information publicly accessible, he says.

Pharmaceutical companies' "marketing techniques and their reluctance to disclose them invite further misgivings about the industry," Troyen Brennan of Aetna Inc., in Hartford, Conn., and Michelle Mello of the Harvard School of Public Health write in an editorial accompanying the study in this week's JAMA The Journal of the American Medical Association.

"Drug companies' attempt to evade regulations may backfire," they conclude, if "public resentment over noncompliance with existing laws sparks demand for additional regulation."