Table 1

Baseline characteristics of participants allocated to usual medical care plus chiropractic care vs. usual medical care alone (n = 750).

	UMC (n = 375)	UMC + CC (n = 375)
Age, years, mean (SD)	30.8 (8.8)	30.9 (8.7)
Sex, n (%)
Male	287 (76.5)	288 (76.8)
Female	88 (23.5)	87 (23.2)
Race, n (%)
White	252 (67.2)	255(68.0)
Black or African American	72 (19.2)	77 (20.5)
Asian	20 (5.3)	10 (2.7)
Native Hawaiian or Other Pacific Islander	2 (0.5)	7 (1.9)
American Indian or Alaska Native	2 (0.5)	0 (0)
Multi-racial	8 (2.1)	6 (1.6)
Unspecified	19 (5.1)	20 (5.3)
Ethnicity, n (%)
Not Hispanic or Latino	286 (76.3)	300 (80.0)
Hispanic or Latino	66 (17.6)	52 (13.9)
Unspecified	23 (6.1)	23 (6.1)
Current LBP episode duration, n (%)
< 7 days	81 (21.6)	73 (19.5)
7 days to < 16 days	40 (10.7)	33 (8.8)
16 days to < 1 month	23 (6.1)	37 (9.9)
1 to 3 months	40 (10.7)	39 (10.4)
> 3 months to < 6 months	23 (6.1)	25 (6.7)
6 months to < 1 year	28 (7.5)	27 (7.2)
1 year or more	140 (37.3)	141 (37.6)
Pain intensity, 0–10, mean (SD)	5.0 (1.9)	5.0 (1.9)
Pain interference, T-score, mean (SD)	58.9 (7.2)	60.0 (7.1)
Physical function, T-score, mean (SD)*	56.8 (7.1)	56.8 (7.3)
Sleep disturbance, T-score, mean (SD)	55.5 (7.6)	55.0 (7.8)
Fatigue, T-score, mean (SD)	51.5 (9.8)	51.8 (10.2)
Anxiety, T-score, mean (SD)	48.1 (9.0)	48.7 (8.7)
Depression, T-score, mean (SD)	45.0 (6.9)	45.8 (7.1)
Social Role, T-score, mean (SD)*	54.6 (9.1)	55.1 (8.9)

*Transformed: 100-(T-score) to make a higher score indicative of worse health;

UMC: usual medical care;

UMC+CC: usual medical care plus chiropractic care;

LBP: low back pain