* Revised 1995 rule to expand scope, lower threshold

* Financial conflicts of scientists in focus since 2008

* From 1996 to 2003, financial support almost tripled

WASHINGTON, Aug 23 (Reuters) - The U.S. National Institutes of Health revised on Tuesday its 16-year-old conflict of interest rules for medical researchers, lowering the amount of money that constitutes a financial conflict and expanding the required disclosures.

The 1995 regulations effectively put responsibility for tracking scientists' financial conflicts of interest on their universities. The rule required researchers to disclose conflicts to their institutions, which then had to assure the NIH the conflict had been managed, reduced or eliminated.

The new rule extends that requirement so researchers report not only the fact of a conflict of interest, but also its details such as value, specific nature, why it is a conflict and the impact it might have on research.

It lowers the amount a researcher must disclose if received from an industry or held in company stock to $5,000 from about $10,000.

Research institutions, in turn, are now required to report that information to the federal grant-awarding agency alongside details of how the conflicts are managed. Also, before spending any grant money, the institution has to post information about the financial conflicts on a public website.

The new rules will affect about 2,000 organizations that are awarded public health science funding every year and some 38,000 scientists who participate in research funded by these grants and have a "significant financial interest," NIH said.

Concern about the integrity of research in the United States has grown since 2008, when Iowa Republican Sen. Charles Grassley criticized prominent Harvard University psychiatrist Dr. Joseph Biederman and others for failing to fully disclose payments from drug companies.

In a more recent example, medical device maker Medtronic Inc (MDT.N) came under fire over accusations that doctors paid by the company had failed to disclose major side effects from a bone growth drug in clinical trials.

A 2009 report by the Institute of Medicine, one of the National Academies of Sciences that advises U.S. policymakers, called on doctors to strictly disclose research funding to strengthen protection against conflicts of interest. The report called for virtually anyone involved in medicine -- academic medical centers, journals, professional societies, researchers and doctors -- to set up or strengthen conflict of interest guidelines.

From 1996 to 2007, relationships between individual academic researchers and industry nearly doubled, according to a study cited by NIH in its final rule. From 1994 to 2003, the amount of financial support for biomedical research almost tripled to $94.3 billion, with 57 percent of that funding coming from industry sources, according to analysis cited by NIH. (Additional reporting by Anna Yukhananov; editing by Andre Grenon)