NEW YORK (Reuters Health) - The mere passage of a law that requires drug companies to disclose how much money they pay doctors may not change physician prescribing practices, suggests a new study.
In two states that passed so-called sunshine laws requiring drugmakers to disclose payments, doctors' choices of which drugs to prescribe for their patients did not differ much from those of peers in states without such a law.
However, since the disclosure of information was to state agencies, not the general public, the state laws were less likely to influence doctors' behavior, one expert not involved in the research noted.
"It was a way of doing a quick analysis to even see if there was an impact we could measure," said Kavita Nair, the study's senior author and a associate professor at University of Colorado School of Pharmacy in Aurora.
Nair and her colleagues said they were trying to gauge the potential effect of a nationwide disclosure requirement.
The Affordable Care Act -- the broad overhaul of the U.S. healthcare system passed in 2010 -- includes a provision that requires drug companies to report certain payments made to doctors. Drug companies may pay doctors for, among other things, consulting, speaking fees or travel.
The reasoning behind disclosure requirements, according to the researchers, is that doctors will shy away from taking money or gifts that might influence their prescribing choices if the information is reported publicly.
In a letter to the Archives of Internal Medicine, Nair's team said they decided to look at the experiences of Maine and West Virginia -- states that each enacted sunshine laws in 2004.
Using information on insurance claims made between July 2003 and March 2009, the researchers analyzed how many prescriptions were written in each state for brand-name cholesterol-lowering statin drugs and brand-name selective serotonin reuptake inhibitor (SSRI) antidepressants.
For comparison, they did the same for demographically similar states without sunshine laws. New Hampshire and Rhode Island were compared to Maine, while Kentucky and Delaware were compared to West Virginia.
The researchers note that patients can get cheaper, generic versions of statins and SSRIs, and drug companies rely on marketing to increase the number of prescriptions written for the brand-name versions.
Overall, "there were negligible to small effects of the disclosure laws in Maine and West Virginia for both statins and SSRIs," Nair's group concluded.
When generic versions of drugs became available, for example, the number of prescriptions for brand-name statins decreased by 45.3 percent in Rhode Island, which did not have a sunshine law. The number of brand-name statin prescriptions decreased by 50.6 percent in Maine.
Though some of the differences the study found were statistically significant, Nair told Reuters Health they weren't large differences, suggesting the sunshine laws were not influencing doctors' behavior.
The researchers acknowledge several limitations in their study, including that other factors could influence the results, the comparison states may be different in other ways and looking at brand-name prescriptions may not be a means to detect the benefits of the laws.
"This doesn't even present a bird's-eye view," said Charles Ornstein, who has looked at the issue of payments to doctors at ProPublica, a non-profit investigative news organization in New York.
Ornstein told Reuters Health that both Maine and West Virginia do not make their disclosures available online. And, he added, companies did not start disclosing how much they paid doctors until 2009 (the end of Nair's study period).
Ornstein thinks the main concern is not the overall prescribing of certain classes of drugs.
"I think as more companies report, and this information has been out there a little longer, you'll see studies that are done with a little more robustness than this one," said Ornstein.
Dr. Jerome Kassirer, a distinguished professor at the Tufts University School of Medicine, said the information also needs to be accessible to researchers.
Kassirer, who has looked at the relationships between doctors and big business, told Reuters Health that the debate comes down to a conflict of interest.
"If I'm going to take advice form a doctor on a new drug or any kind of procedure, I'd like the advice from someone who is not conflicted," said Kassirer.
And both Ornstein and Kassirer said sunshine laws -- not just in Maine and West Virginia -- have seen results.
"I think it's happened already -- at least anecdotally," said Kassirer.
(This story is corrected to reflect Maine and West Virginia do not report their disclosures online and companies did not start reporting their disclosures until 2009 in paragraph 17)
SOURCE: bit.ly/Ky4KWP Archives of Internal Medicine, online May 28, 2012.