A few interesting things here. First, public and private funding have increased at roughly the same rate. Randall notes that
It is amazing that after such a huge increase across the board that the relative size of private and public contributions should have emerged unchanged
Randall quotes from the original paper, which appeared in the September 21 issue of JAMA:
The United States spent an estimated 5.6 percent of its total health expenditures on biomedical research, more than any other country, but less than 0.1 percent for health services research. From an economic perspective, biotechnology and medical device companies were most productive, as measured by new diagnostic and therapeutic devices per dollar of research and development cost. Productivity declined for new pharmaceuticals.
To me, 5-6% of health care spending going to biomedical research sounds about right. I'm going to have to get the paper to see how other countries stack up.