Human ecology and the geographic distribution of physician assistants

Ecological characteristics of states were correlated with measures of the geographic distribution of physician assistants, and, for comparative purposes, of new physician licenses. It was hypothesized that prior physician-to-population ratios, the distribution of physician assistant training opportunities, and the nature of state laws regulating physician assistants also would affect the geographic distribution of physician assistants. Population size, of course, is strongly correlated with the total number of both groups in the various states. When numbers relative to population are considered, physician assistants are concentrated in states with extensive training opportunities and, to a lesser extent, favorable laws. In contrast, new physician licenses tend to be concentrated in states that already have high physician-to-population ratios.