Making existing interventions more effective is the next step in addressing the AIDS pandemic, according to noted physician, author, and teacher Paul Farmer.

“I’m surprised at the ineffectiveness of social projects,” he told an audience of more than 400 Thursday at the Clinton Presidential Center. “They are not focused on the outcome.”

Farmer, the incoming chair of the Department of Global Health and Social Medicine at Harvard University, said the world has progressed beyond a “low point” of the AIDS epidemic in 2002 when average drug costs were more than $10,000 per patient annually. “This was the time when people were saying not a lot could be done,” Farmer said.

Since then, the cost of AIDS drugs has declined dramatically. In addition, inroads have been made in Haiti, where the proportion of the population infected with HIV has dropped from 5 percent to 2 percent.

Farmer also called for renewed efforts to address other health crises around the world, singling out tuberculosis and infant mortality. “These are overwhelming problems, but they’re problems that have solutions as well,” Farmer said.

Farmer, the subject of the biography “Mountains Beyond Mountains,” also described his time practicing medicine in Haiti and Rwanda.

“He defined service and outcomes the way I’ve tried to for years,” said Skip Rutherford, dean of the Clinton School of Public Service at the University of Arkansas. “To have someone like Paul Farmer is a thrill to everyone.”