Appendix Table 1.

Comparison of Family Medicine Emergency Physicians with Isolated Family Medicine or Dual Family Medicine and Emergency Medicine Board Certification, n = 3596

	Isolated FM Board Certification (n = 2860)		Dual FM and EM Board Certification (n = 736)
Characteristics	n	%	n	%	P Value^*
Demographics
Age, y (median [IQR])	2860	63 (58 to 67)	736	69 (66 to 72)	<0.001
Age categories, y					<0.001
25 to 44	93	3	17	2
45 to 64	1573	55	128	17
≥65	1194	42	591	80
Female sex	364	13	65	9	0.004
International medical graduate	512	18	77	10	<0.001
Geography
US Census division					<0.001
New England	108	4	41	6
Mid Atlantic	216	8	65	9
East North Central	395	14	101	14
West North Central	303	11	46	6
South Atlantic	583	20	145	20
East South Central	295	10	46	6
West South Central	426	15	65	9
Mountain	216	8	89	12
Pacific	306	11	135	18
MSA population size					<0.001
≥1,000,000	1036	36	331	45
250,000 to 999,999	617	22	184	25
100,000 to 249,999	310	11	88	12
<100,000	42	1	12	2
Unknown	855	30	121	16
Urban influence					<0.001
Urban	2142	75	639	87
Large rural	409	14	70	10
Small rural	297	10	25	3
Training
Residency					<0.001
Emergency medicine	29	1	147	20
Family medicine	2665	93	516	70
Internal medicine	14	0.5	15	2
Pediatrics	3	0.1	3	0.4
Surgery	26	0.9	12	2
Internship only	35	1	23	3
Other residency	6	0.2	7	1
None	82	3	13	2
Years since completed medical training					0.002
<5	29	1	5	0.7
5 to 9	53	2	26	4
10 to 19	350	13	65	9
≥20	2346	84	627	87
Primary specialty of emergency medicine	1402	49	602	82	<0.001

EM, emergency medicine; FM, family medicine; IQR, interquartile range; MSA, metropolitan statistical area.
↵* Bivariate comparisons were tested using Kruskal-Wallis, χ², and Fisher's exact tests, as appropriate.