The CMS recently released its rules on the Physician Payments Sunshine Act, which calls for increased transparency on the financial relationships between physicians and drug and device manufacturers, while a new report provides some light on why such legislation may have been needed.

The report analyzed pharmaceutical research studies and found that industry-sponsored drug studies were more likely to report greater benefits for the particular drug being studied—but the report couldn't say why this is so. It noted that these results “cannot be explained by standard 'risk of bias' assessment tools.”

The full analysis (PDF) was written by researchers from the U.S., Canada and Denmark and published by the Cochrane Collaboration, an independent, international research organization based in the U.K. A summary was written by the U.S. researcher involved in the Cochrane review, Lisa Bero, with the University of California San Francisco's department of clinical pharmacy and health policy, and it was published in the American Medical Association's JAMA Internal Medicine (formerly known as the Archives of Internal Medicine).

The researchers reviewed 48 papers published between 1986 and 2010. The papers were systematic reviews of other studies with a median number of 137 studies per paper. The number of studies included in each of the 48 reviews ranged from nine to 930.

The researchers found that the number of studies with favorable results were about 24% higher among industry-sponsored studies. Industry-sponsored studies were also less likely to show evidence of harm and more likely to reach “favorable overall conclusions,” according to the report.

In her JAMA Internal Medicine summary, Bero wrote that no differences were found in the “methodological characteristics” between industry- and non-industry-sponsored studies. In fact, she said industry-sponsored studies “generally reported adequate blinding more often than non-industry-sponsored studies.”

Despite the lack of a conclusive reason for the findings, Bero wrote that the findings still have important implications.

“Decision makers must take sponsorship into account when evaluating whether they should base clinical practice and reimbursement on the results of a study,” Bero wrote. “Clinical practice guidelines, which are increasingly based on systematic reviews, should be made more transparent by disclosing the sponsorship of studies included in the guideline and by regarding industry sponsorship as a factor that increases the risk of bias.”

She concluded that, while improved transparency may be an alert for the potential of bias, it will not eliminate it.

As for the Sunshine Act, its co-sponsor, Sen. Chuck Grassley (R-Iowa), pledged to “stay vigilant about how this law is implemented.”

“Disclosure brings about accountability, and accountability will strengthen the credibility of medical research, the marketing of ideas and, ultimately, the practice of medicine,” Grassley said in a news release. “The lack of transparency regarding payments made by the pharmaceutical and medical device community to physicians has created a culture that this law should begin to change substantially.”

The Pharmaceutical Research and Manufacturers of America trade association released a statement of its own that sounded similar to Grassley's: “PhRMA remains committed to the principles of the Sunshine Act and continues to believe that careful implementation is essential to ensuring that Sunshine fulfills its objective of usable, transparent and understandable sharing of information.”

Dr. Jeremy Lazarus, president of the American Medical Association, wrote in a blog post that “the AMA has long supported transparency generally to ensure such relationships are independent and focused on benefiting patients,” but it has also worked to make sure implementation is “not burdensome to physicians” and that doctors had the right to challenge reports they deemed false or misleading.

“Many of physicians' interactions with manufacturers are essential for the advancement of medicine, from spurring medical innovations to generating research-based insights into treatments,” Lazarus wrote. “The AMA is working to ensure the new database serves to foster—not disrupt—those ties that aim to help improve patient care.”