Combined U.S. public and private investment in biomedical and health research dropped by $4 billion in 2011, according to a new report by Research!America.

It was the first reported decline since the group began keeping track in 2002. Research!America promotes medical research funding.

Most of the drop was associated with the end of $10.4 billion in research funding directed through the National Institutes of Health as part of the American Reinvestment and Recovery Act, the federal economic stimulus package that was passed in 2009.

"This decline in federal funding, which follows several years of lost purchasing power, is compromising our nation’s ability to capitalize on unprecedented scientific opportunity," the report stated. "It comes at a time when other nations are ramping up their own investments in research to fuel economic growth and global competitiveness."

According to the study, research and development spending by private industry increased slightly. University spending was up about 5 percent. But government and other forms of research funding, including philanthropic, decreased.

Total U.S. spending on the research totaled an estimated $136.2 billion in 2011, a 3 percent decline from the previous year, according to the report.