Iowa continues to see a steady increase in its supply of doctors, despite gloomy predictions that physicians would flee the profession because of big changes in health care. A new report from the Iowa Board of Medicine says 6,829 physicians worked in the state last year. That was up 2 percent from 2012, and up 12 percent from 2006. Iowa continues to have fewer doctors per capita than average, and it faces significant doctor shortages in some medical specialties and rural regions. But overall, Iowa’s supply of doctors has risen much faster than the state’s population over the past three decades.