Physician Assistants in Primary Care: Trends and Characteristics

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Figure 1
Percentage of physician assistants practicing in primary care by demographic characteristics: point estimates and 95% confidence intervals.
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Figure 2
Trend in the percentage of primary care PAs by year of graduation from 1975 to 2008. PA = physician assistant.

Note: Trend analysis (regression) included data for all responding graduates. Plot was started at graduation year of 1975 because of limited data from PAs graduating between 1965 and 1974.

Table 1

Demographic Characteristics of Primary Care vs Non–Primary Care Physician Assistants

Characteristic	All, % (N = 18,048)	Non–PrimaryCare, No.(n = 12,015)	Primary Care, No. (n = 6,033)	Primary Care, % (95% CI)	Odds Ratio (95% CI)	P Value^a
Sex
Female	64.7	7,337	3,909	34.8 (33.9-35.6)	1.21 (1.13-1.30)	<.001
Male	35.3	4,271	1,876	30.5 (29.3-31.7)	Ref
Race, categorical						<.001
Asian/Pacific Islander	4.0	466	186	28.5 (25.1-32.2)	0.81 (0.68-0.96)	.02
Black	2.8	299	162	35.1 (30. 8 -39.7 )	1.10 ( 0.9 0 -1.33)	.34
Hispanic	3.7	335	262	43.9 (39.9-48.0)	1.59 (1.34-1.87)	<.001
American Indian	<1	59	41	41.0 (31.3-51.3)	1.41 (0.94-2.09)	.09
Other	<1	59	16	21.3 (12.7-32.3)	0.55 (0.31-0.93)	.03
Race, dichotomous
White	88.4	9,582	4,726	33.0 (32.3-33.8)	Ref
Nonwhite^b	11.6	1,218	667	35.4 (33.2-37.6)	1.11 (1.00-1.23)	.04
		Mean			Mean Difference (95% CI)
Age, y	–	40.2	42.4	–	2.2 (1.9-2.6)	<.001^c
Age at graduation, y	–	30.0	31.0	–	1.0 (0.8-1.2)	<.001^c

Ref = reference category for odds ratios.
Notes: All percentages were calculated from nonmissing data. A total of 1,560 physician assistants were excluded because of incomplete questionnaires.
a Unless otherwise noted, the Fisher exact test was used to calculate P values.
b Sum of categories other than white.
c Two - sample t test.

Table 2

Trends in Primary Care Practice Among Physician Assistants by Demographic Characteristics

	All Graduates		2004-2008 Graduates
Characteristic	P Value	Estimated Mean Change per Year, %	P Value	Estimated Mean Change per Year, %
Overall by graduation Year	<.0001	–0.3	.02	0.9
Sex by graduation year
Male	<.0001	–0.4	.72	0.3
Female	<.0001	–0.3	.02	1.1
Race, dichotomous, by graduation year
White	<.0001	–0.3	.08	0.8
Nonwhite	.06	–0.2	.06	2.2
Race, categorical, by graduation year
Asian/Pacific Islander	.50	–0.1	.003	5.3
Black	.40	–0.4	.88	–0.4
Hispanic	.61	–0.1	.66	–0.9
American Indian	.44	–0.2	.71	0.4
Other	.36	–5.8	.52	–0.5
Overall by age at questionnaire completion	<.0001	0.4	.01	0.2
≤40 y	.67	–0.1	.92	0.0
>40 y	<.0001	0.5	.20	0.4
Overall by age at graduation (≥20 y)	<.0001	0.5	.004	0.3

Notes: χ² trend tests were used to determine if the proportion of physician assistants in primary care varied across characteristics. The mean change per year was estimated using linear regression analyses of proportions on year, weighted with the variance of the proportion for the given year.