Table 1.

Description of the Sample for Initial Medical Encounter for Chronic Musculoskeletal Pain

Characteristic		Weighted Frequency	Proportion
Patient characteristics	Age category:
	<24	32423,449	9.8
	25 to 44	73083,718	22.1
	45 to 64	130756,571	39.5
	65 to 74	50940,316	15.4
	≥75	43619,913	13.2
	Female	197197,657	59.6
	Male	133626,408	40.4
	Race/ethnicity:
	White	235032,758	71.0
	Black	34957,028	10.6
	Hispanic	41253,280	12.5
	Other	19580,999	5.9
	Smoking:
	Not currently	202897,165	82.3
	Currently	43635,223	17.7
	Payment source:
	Self-pay	11658,639	3.7
	Private insurance	178058,216	56.0
	Medicare	84959,930	26.7
	Medicaid/CHIP	26321,488	8.3
	Workers' comp	9294,455	2.9
	Other^*	7291,229	2.3
Physician and practice characteristics	Specialty:
	Family physician	118232,869	35.7
	Pediatrician	11321,066	3.4
	Internal medicine	68549,867	20.7
	Orthopedist	73700,336	22.3
	Neurologist	5785,281	1.8
	Other	53234,646	16.1
	Physician degree:
	MD	296458,726	89.6
	DO	34365,339	10.4
	Type of practice:
	Solo	104086,387	31.5
	Nonsolo (group)	226710,085	68.5
	Office type:
	Private practice	296241,089	89.6
	All other^†	34582,976	10.4
	EMR:
	Yes, all	195712,417	59.3
	Yes, part	38619,680	11.7
	No	95852,845	29.0
Survey year	2007	33040,563	10.0
	2008	31277,438	9.4
	2009	33262,636	10.0
	2010	37958,504	11.5
	2011	33019,687	10.0
	2012	35868,624	10.8
	2013	35906,759	10.8
	2014	38721,711	11.7
	2015	51768,143	15.6

↵* Source of payment other: charity, unknown, other.
↵† Office type—all other: office setting all other; free-standing clinics/urgicenter; federally qualified health center; mental health center; non–federal government clinic; family planning clinic; health maintenance organization or other prepaid practice; faculty practice plan.
CHIP, Children's Health Insurance Program; EMR, electronic medical record.