Table 4

U.S. Population with chronic spine pain who visited a chiropractor from NHIS & MEPS relative to trial participants

	U.S. Population who visited a chiropractor		Trial Population			Trial – U.S. Population
	% or Mean (SD)	SE	% or Mean (SD)	SE	N	Difference	P-value	Effect Size
Age†
18 to 30	13.7%	0.008	7.0%	0.007	101	-6.7%	< 0.001	0.22
31 to 50	44.7%	0.011	32.8%	0.012	473	-12.0%	< 0.001	0.24
51 to 64	26.3%	0.009	23.5%	0.011	339	-2.8%	0.057	0.06
65 to 84	14.2%	0.007	35.9%	0.013	518	21.7%	< 0.001	0.51
85 and above	1.1%	0.002	0.8%	0.002	12	0.3%	0.41	0.03
Sex†
Male	44.1%	0.011	40.7%	0.013	588
Female	55.9%	0.011	59.3%	0.013	856	3.4%	0.048	0.07
Race†
Alaskan Native, or American Indian	1.2%	0.002	0.9%	0.002	13	-0.3%	0.46	0.03
Asian or Pacific Islander	1.8%	0.003	1.2%	0.003	17	-0.6%	0.13	0.05
Black/African American	7.6%	0.005	2.3%	0.004	33	-5.3%	< 0.001	0.25
Other Race	0.3%	0.001	0.7%	0.002	10	0.4%	0.026	0.06
Multiple Race	0.2%	0.001	0.1%	0.001	1	-0.1%	0.35	0.03
White	89.0%	0.006	94.9%	0.006	1368	5.8%	< 0.001	0.22
Ethnicity†
Hispanic	8.7%	0.006	1.3%	0.003	19	-7.3%	< 0.001	0.37
Not Hispanic	91.3%	0.006	98.7%	0.003	1419
Employment†18–64 years old
Not Employed	34.6%	0.013	19.9%	0.013	178
Employed	65.4%	0.013	80.1%	0.013	716	14.6%	< 0.001	0.33
65 years or older
Not Employed	85.1%	0.018	80.4%	0.017	426
Employed	14.9%	0.018	19.6%	0.017	104	4.7%	0.07	0.12
Education†
Less than high school	14.2%	0.008	1.7%	0.003	24	-12.5%	< 0.001	0.51
High school	29.6%	0.010	20.4%	0.011	291	-9.2%	< 0.001	0.21
College, no degree	23.0%	0.009	21.5%	0.011	306	-1.5%	0.28	0.04
Associate or technical school	13.0%	0.008	11.9%	0.009	170	-1.1%	0.34	0.03
Bachelor’s	12.8%	0.008	28.6%	0.012	407	15.7%	< 0.001	0.40
Post-graduate or professional	7.3%	0.006	15.9%	0.010	227	8.6%	< 0.001	0.27
Household Income†
$0 - $34,999	38.6%	0.011	29.5%	0.013	353	-9.1%	< 0.001	0.19
$35,000 - $74,999	35.2%	0.011	45.8%	0.014	548	10.6%	< 0.001	0.22
$75,000+	26.2%	0.011	24.7%	0.012	296	-1.5%	0.38	0.03
Body Mass Index†
Underweight	0.7%	0.002	0.6%	0.002	8	-0.1%	0.63	0.01
Healthy weight	30.0%	0.010	31.9%	0.012	461	2.0%	0.22	0.04
Overweight	36.5%	0.011	36.4%	0.013	526	-0.1%	0.96	0.00
Obese	32.8%	0.010	31.1%	0.012	449	-1.7%	0.28	0.04
Pain Duration†
1 year or less	13.9%	0.008	21.0%	0.011	296	7.1%	< 0.001	0.19
1 to 5 years	29.2%	0.010	32.8%	0.013	461	3.6%	0.028	0.08
5 to 10 years	19.9%	0.009	18.8%	0.010	265	-1.1%	0.42	0.03
Over 10 years	37.0%	0.010	27.4%	0.012	385	-9.6%	< 0.001	0.21
Radiating Pain†
No	46.6%	0.011	60.0%	0.013	866
Yes	53.4%	0.011	40.0%	0.013	578	-13.3%	< 0.001	0.27
Diabetes†
No	90.4%	0.006	93.8%	0.006	1355
Yes	9.6%	0.006	6.2%	0.006	89	-3.4%	< 0.001	0.13
Smoking†
No	73.7%	0.010	90.3%	0.008	1304
Yes	26.3%	0.010	9.7%	0.008	140	-16.6%	< 0.001	0.44
Alcohol Use†
No	31.7%	0.010	41.5%	0.014	521
Yes	68.3%	0.010	58.5%	0.014	735	-9.8%	< 0.001	0.20
SF-12/36 PCS*	44.9 (11.7)	0.323	43.0 (8.1)	0.216	1424	-1.9	< 0.001	0.16
SF-12/36 MCS*	50.4 (10.0)	0.284	53.5 (9.1)	0.241	1424	3.1	< 0.001	0.31
QALYs*	0.762 (0.17)	0.005	0.760 (0.13)	0.004	1414	0.002	0.70	0.01

† Data from NHIS using 3006 observations representative of 2,315,852 U.S. adults

*Data from MEPS using 2870 observations representative of 4,194,660 U.S. adults

MCS = mental component score; N = number; PCS = physical component score; QALYs = Quality-adjusted life years; SD = standard deviation; SE = standard error