Appendix Table 2.

Demographic Characteristics, by Clinician Type, in Hospital Clinics (NHAMCS)^*

Characteristic	Physician (Reference) (n = 13 359)	Nurse Practitioner Only (n = 1400)	P Value	Nurse Practitioner and Physician (n = 191)	P Value	Physician Assistant Only (n = 1152)	P Value	Physician Assistant and Physician (n = 204)	P Value
Mean age, y	45.0	42.2	0.003	46.3	0.58	42.1	0.006	44.2	0.63
Female	64.4	67.1		58.3		66.7		63.7	0.51†
Race/ethnicity									0.002†
White	70.6	81.4		59.2		82.0		67.2
Black	16.7	8.3		17.7		9.3		8.1
Hispanic	9.7	6.3		20.0		6.3		14.7
Other	3.0	4.0		3.1		2.5		10.0
Mean Charlson comorbidity count	0.049	0.021	<0.001	0.059	0.68	0.015	<0.001	0.039	0.70
Acute symptoms	75.0	89.6		75.4		88.7		81.2	<0.001†
Insurance									0.007†
Private	46.0	41.8		45.8		43.4		28.3
Medicare/Medicaid	33.4	34.5		37.4		28.7		41.2
Other	20.6	23.7		16.8		27.9		30.5
Provider identifies as PCP	52.8	59.3		28.0		49.6		38.0	0.027†
Urban location	81.7	51.2		83.9		39.5		74.3	<0.001†
Region									0.126
Northeast	17.6	19.4		12.9		14.4		28.1
Midwest	37.2	26.0		33.1		25.1		16.6
South	30.8	45.4		37.6		35.8		26.6
West	14.4	9.3		16.5		24.7		28.6
Symptom group
URIs	37.1	43.8		35.7		42.0		31.8	0.046†
Back pain	46.0	38.0		53.1		43.3		47.6	0.060†
Headache	18.1	20.0		12.9		16.2		20.6	0.178†

NHAMCS = National Hospital Ambulatory Medical Care Survey; PCP = primary care provider; URI = upper respiratory infection.

^*Values are percentages unless otherwise indicated and may not sum to 100 due to rounding. Boldface values indicate comparisons with P < 0.05.

^†Represents global chi-square tests among all clinician subtypes.