Stanford University has taken disciplinary action against five faculty members at its medical school after determining they violated school policy by giving paid promotional speeches for drug companies, a spokesman said.

The move followed a ProPublica investigation in December that found Stanford and other teaching hospitals weren't enforcing their own conflict-of-interest rules.

At Stanford, which has one of the nation's toughest policies, ProPublica identified more than a dozen faculty members—including medical staff leaders—who were paid speakers.

Paul Costello, a Stanford spokesman, declined to identify the disciplined faculty members or discuss their penalties. But in a written statement he said the "actions are significant" and have affected or could affect the doctors' compensation or positions.

Stanford is one of several medical schools that took action against faculty members, overhauled conflict-of-interest policies or provided additional education to staff members following ProPublica's report.

Conflict-of-interest policies have become increasingly common at medical schools and teaching hospitals, reflecting concerns that promotional talks undermine the credibility of both the physicians giving them and the institutions they represent.

Yet when it comes to enforcing the policies, ProPublica found, the schools largely have relied on the honor system, allowing physicians to interpret the rules as they see fit.

We found physicians who were violating school policies by comparing staff lists of a dozen medical schools and teaching hospitals with our Dollars for Docs database. The database contains the payments publicly reported by seven drug companies for speaking and consulting by doctors. (An eighth firm has since been added; ProPublica will publish an update to the database in coming weeks.)

Among them was Dr. Alan Yeung, Stanford's chief of cardiovascular medicine, who earned $64,000 from Eli Lilly & Co. in 2009 and 2010. Yeung was also the vice chairman of the Department of Medicine but left that position in February, Costello said. He declined to say whether the move was related to Yeung's violation of the policy.

Yeung did not respond to a request for comment. In an email last year, Yeung said he had stopped speaking for Lilly. "I take full responsibility for this error," he said.

At the University of Colorado School of Medicine, the executive committee approved new rules this week explicitly prohibiting physicians from participating in drug company speaker's bureaus.

The medical school's 2008 policy banned faculty from speaking on behalf of companies if "the content of the lectures, slides, references or educational handouts is subject to approval by industry representatives." But university officials said some faculty apparently didn't fully understand it.

The new rules "clearly prohibit participation in marketing" but allow appropriate "research and educational opportunities," spokeswoman Jacque Montgomery said in an email.

University of Colorado officials interviewed the 13 medical school physicians identified by ProPublica as paid speakers and "accepted their good faith interpretations of the policy," Montgomery said. None were terminated or suspended, she said.

The medical school's dean plans to launch an educational campaign to ensure faculty members understand the new rules.

The Association of American Medical Colleges, a trade group, does not track how its members enforce conflict-of-interest policies. But the issue has become a hot topic, said Heather Pierce, the group's senior director for science policy and regulatory counsel.

Among schools that have checked their faculty against drug company databases, she said, "the number of truly problematic situations is relatively small."

Changes in federal rules and laws may require even more disclosure of payments to medical school faculty—and potentially more monitoring by school officials.

The National Institutes of Health is formulating rules that may require schools to disclose researchers' conflicts of interest online. As it stands now, a federal law will require all drug and medical device companies to publicly report their payments to physicians beginning in 2013.

"Our member institutions are continuing to work to ensure that their policies best reflect their practices, all toward the goal of ensuring that physicians and researchers maintain public trust," Pierce said.

Among other schools identified in ProPublica's story last year:

• The University of Pennsylvania said it is in the process of clarifying its policy after ProPublica found 20 Penn speakers in its database.

  Penn's 2006 policy states that faculty "should not participate in industry marketing activities." Penn's chief medical officer, Dr. P.J. Brennan, had said he interpreted that to prohibit delivering drug-company lectures, but in a recent email, he said the clarifications will make this explicit.

  Susan Phillips, chief of staff for Penn Medicine, said no faculty members were disciplined, but there is now a "heightened awareness of the policy and what it means."

• The University of California, San Francisco, said its compliance office has looked into about 15 possible policy violations since ProPublica's article, but spokeswoman Amy Pyle said she could not discuss the outcome of the reviews, even in general.

  In a statement, Pyle said the school is beefing up its conflict-of-interest office and is in the process of creating a central system to track faculty and employee conflict-of-interest disclosures. The school also continues to educate faculty members about its policy, she said.

• The University of Pittsburgh said it evaluated the contracts of 22 faculty members ProPublica identified as speakers. "All potential instances of non-compliance with our policy are investigated and appropriately addressed on a timely basis," said Dr. Barbara Barnes, an associate vice-chancellor in charge of industry relationships, in a written statement. "We are also adding additional resources to help us educate employees about the requirements of the policy, to provide consultation on specific issues, and to monitor compliance."

  Spokeswoman Wendy Zellner declined to say whether any faculty members had been disciplined.