Special areas of interest have been international medicine, wilderness medicine, domestic violence and homeless healthcare. In 1992 he created Operation Safety Net as part of the Pittsburgh Mercy health system to provide healthcare to the unsheltered homeless. In 2005 he initiated the annual International Street Medicine Symposium and in 2009 he and others created the Street Medicine Institute. Through extensive travel, speaking and consultations he has spearheaded the spread of the global street medicine movement.