Background: The physician assistant (PA) profession is a nationally recognized medical profession
in the United States of America (USA). However, relatively little is known regarding national trends
of the PA workforce.
Methods: We examined the 1980-2007 USA Census data to determine the demographic
distribution of the PA workforce and PA-to-population relationships. Maps were developed to
provide graphical display of the data. All analyses were adjusted for the complex census design and
analytical weights provided by the Census Bureau.
Results: In 1980 there were about 29 120 PAs, 64% of which were males. By contrast, in 2007
there were approximately 97 721 PAs with more than 66% of females. In 1980, Nevada had the
highest estimated rate of 40 PAs per 100 000 persons, and North Dakota had the lowest rate
(three). The corresponding rates in 2007 were about 85 in New Hampshire and ten in Mississippi.
The levels of PA education have increased from less than 21% of PAs with four or more years of
college in 1980, to more than 65% in 2007. While less than 17% of PAs were of minority groups in
1980, this figure rose to 23% in 2007. Although nearly 70% of PAs were younger than 35 years old
in 1980, this percentage fell to 38% in 2007.
Conclusion: The trends of sustained increase and geographic variation in the PA workforce were
identified. Educational level, percentage of minority, and age of the PA workforce have increased
over time. Major causes of the changes in the PA workforce include educational factors and federal
legislation or state regulation.