Dose-Response and Efficacy of Spinal Manipulation for Care of Chronic Low Back Pain: A Randomized Controlled Trial

doi:10.1016/j.spinee.2013.07.468

Table 4

Secondary Outcomes

	Observed unadjusted Mean (SD)				Slope (95%CI)	Adjusted Mean difference (95% CI)
	SMT 0	SMT 6	SMT 12	SMT 18	per 6 SMT sessions	SMT 0 vs SMT 6	SMT 0 vs SMT 12	SMT 0 vs SMT 18
Pain unpleasantness (0-100 scale)
0 wk	41.7 (19.5)	41.1 (21.1)	40.3 (22.8)	42.4 (22.2)
6 wk	24.7 (21.7)	20.3 (17.5)	15.6 (17.3)	18.4 (18.1)	2.4 (0.9, 4.0)^{^*}	4.2 (−0.8, 9.1)	8.7 (3.5, 14.0)^{^*}	6.6(1.7, 11.6)^{^*}
12 wk	29.7 (22.3)	24.5 (20.6)	22.2 (22.3)	23.9 (21.3)	2.0 (0.2, 3.7)	4.8 (−1.0, 10.5)	7.1 (1.1, 13.0)^{^*}	5.8 (0.1, 11.5)
18 wk	26.8 (22.3)	21.9 (21.2)	20.4 (20.4)	21.3 (21.8)	1.8 (0.1, 3.6,)	4.6 (−1.0, 10.3)	5.8 (0.4, 11.2)	5.8 (0.4, 11.2)
24 wk	27.4 (21.7)	24.8 (21.8)	25.0 (21.9)	24.8 (22.4)	0.7 (−1.1, 2.5)	2.1 (−3.5, 7.8)	2.0 (−3.6, 7.5)	2.5 (−3.2, 8.3)
39 wk	28.3 (21.6)	25.5 (21.3)	23.2 (20.8)	23.0 (21.1)	1.8 (0.1, 3.6)	2.4 (−3.3, 8.2)	4.8 (−0.6, 10.3)	5.4 (−0.2, 10.9)
52 wk	27.8 (22.1)	22.1 (21.7)	24.0 (24.0)	21.5 (19.9)	1.7 (−0.1, 3.5)	5.4 (−0.3, 11.2)	3.7 (−2.4, 9.7)	6.4 (0.7, 12.1)

Days with pain (last 4 wk)
0 wk	24.8 (4.8)	24.1 (5.5)	23.3 (5.7)	24.1 (4.6)
6 wk	18.9 (10.0)	17.6 (10.6)	15.0 (10.1)	16.3 (10.8)	0.8 (−0.0, 1.7)	0.9 (−1.8, 3.5)	3.0 (0.3, 5.6)	2.2 (−0.6, 4.9)
12 wk	18.1 (9.5)	17.4 (9.2)	15.5 (9.7)	14.7 (10.2)	1.1 (0.2, 1.9)^{^*}	0.4 (−2.0, 2.8)	1.9 (−0.7, 4.5)	3.0 (0.5, 5.6)^{^*}
18 wk	17.4 (10.2)	17.6 (10.3)	15.5 (10.3)	14.9 (10.6)	0.8 (−0.0, 1.7)	−0.6 (−3.2, 2.1)	1.2 (−1.5, 3.9)	2.2 (−0.6, 4.9)
24 wk	16.9 (10.0)	16.5 (10.3)	15.4 (9.5)	13.5 (9.6)	1.0 (0.2, 1.8)^{^*}	0.1 (−2.5, 2.7)	0.7 (−1.8, 3.3)	3.1 (0.5, 5.7)^{^*}
39 wk	17.7 (9.8)	15.6 (9.9)	15.1 (10.4)	14.3 (10.6)	0.9 (0.1, 1.7)	1.7 (−0.8, 4.2)	1.7 (−0.8, 4.3)	3.0 (0.4, 5.6)
52 wk	17.0 (10.2)	15.3 (10.3)	14.0 (10.6)	13.6 (10.4)	1.0 (0.1, 1.8)^{^*}	1.3 (−1.4, 3.9)	2.1 (−0.7, 4.9)	3.0 (0.3, 5.7)

Days with disability (last 4 wk)
0 wk	7.4 (8.1)	6.7 (7.5)	6.8 (7.5)	6.5 (7.2)
6 wk	2.4 (5.5)	1.6 (3.0)	1.3 (2.7)	1.2 (3.4)	0.3 (−0.0, 0.7)	0.8 (−0.4, 1.9)	1.0 (−0.1, 2.2)	1.1 (−0.1, 2.3)
12 wk	3.4 (5.9)	2.6 (4.9)	2.0 (3.3)	2.3 (3.7)	0.4 (−0.0, 0.7)	0.6 (−0.7, 1.9)	1.3 (0.0, 2.5)	1.0 (−0.3, 2.2)
18 wk	2.1 (5.3)	2.2 (5.0)	1.8 (4.1)	2.1 (4.9)	0.1 (−0.4, 0.5)	−0.1 (−1.4, 1.3)	0.3 (−0.9, 1.6)	0.0 (−1.3, 1.4)
24 wk	3.5 (6.7)	2.7 (5.1)	2.8 (4.6)	2.8 (4.2)	0.1 (−0.3, 0.6)	0.7 (−0.7, 2.1)	0.6 (−0.8, 2.1)	0.5 (−0.9, 1.9)
39 wk	2.8 (5.1)	3.0 (5.5)	2.4 (4.7)	2.5 (4.8)	0.1 (−0.3, 0.5)	−0.3 (−1.7, 1.1)	0.4 (−0.9, 1.6)	0.2 (−1.1, 1.5)
52 wk	3.4 (6.0)	3.4 (6.9)	1.9 (3.7)	2.4 (4.7)	0.4 (−0.1, 0.8)	−0.1 (−1.7, 1.4)	1.5 (0.2, 2.8)	0.8 (−0.6, 2.1)

Perceived pain change (6-pt Likert)^{^†}
6 wk	3.7 (0.9)	4.1 (0.9)	4.3 (1.0)	4.3 (1.0)	0.1 (0.1, 0.2)^{^*}	0.2 (−0.0, 0.5)	0.4 (0.2, 0.7)^{^*}	0.4 (0.1, 0.7)^{^*}
12 wk	3.7 (0.9)	3.8 (0.9)	4.0 (1.0)	4.0 (0.9)	0.1 (0.0, 0.2)	0.1 (−0.1, 0.4)	0.3 (−0.0, 0.5)	0.3 (0.0, 0.5)
18 wk	3.7 (0.9)	4.0 (1.0)	4.1 (1.0)	4.0 (1.0)	0.1 (−0.0, 0.2)	0.2 (−0.0, 0.5)	0.4 (0.1, 0.7)^{^*}	0.2 (−0.0, 0.5)
24 wk	3.8 (1.0)	3.9 (1.0)	3.9 (1.0)	3.9 (1.0)	0.0 (−0.1, 0.1)	0.1 (−0.2, 0.4)	0.1 (−0.2, 0.4)	0.1 (−0.2, 0.3)
39 wk	3.7 (1.0)	3.8 (1.1)	4.0 (1.0)	4.0 (0.9)	0.1 (0.0, 0.2)	0.1 (−0.2, 0.4)	0.3 (0.0, 0.6)	0.3 (0.0, 0.5)
52 wk	3.7 (0.9)	4.0 (1.1)	3.9 (1.1)	4.0 (0.9)	0.1 (−0.0, 0.1)	0.3 (0.0, 0.6)	0.2 (−0.1, 0.5)	0.2 (−0.0, 0.5)

Perceived disability change (6-pt Likert)^{^†}
6 wk	3.6 (0.9)	3.9 (0.9)	4.0 (1.0)	4.0 (0.9)	0.1 (0.0, 0.2)^{^*}	0.3 (0.0, 0.5)	0.4 (0.1, 0.6)^{^*}	0.4 (0.2, 0.6)^{^*}
12 wk	3.5 (0.9)	3.8 (0.9)	3.8 (1.0)	3.8 (0.9)	0.1 (0.0, 0.2)^{^*}	0.2 (0.0, 0.5)	0.3 (0.0, 0.5)	0.3 (0.0, 0.5)
18 wk	3.6 (0.8)	3.7 (1.0)	3.8 (1.0)	3.8 (0.9)	0.1 (−0.0, 0.2)	0.1 (−0.2, 0.3)	0.2 (−0.1, 0.4)	0.2 (−0.0, 0.5)
24 wk	3.6 (0.9)	3.7 (0.9)	3.7 (0.9)	3.7 (1.0)	0.0 (−0.1, 0.1)	0.1 (−0.2, 0.3)	0.1 (−0.2, 0.3)	0.1 (−0.2, 0.4)
39 wk	3.6 (0.9)	3.7 (1.0)	3.9 (1.0)	3.9 (0.9)	0.1 (0.0, 0.2)^{^*}	0.1 (−0.2, 0.4)	0.3 (0.1, 0.6)^{^*}	0.3 (0.0, 0.5)^{^*}
52 wk	3.6 (0.9)	3.8 (1.0)	3.8 (1.1)	3.9 (0.9)	0.1 (−0.0, 0.2)	0.2 (−0.0, 0.5)	0.2 (−0.1, 0.5)	0.3 (0.0, 0.3)

SF-12 physical health component
0 wk	43.0 (9.5)	43.8 (8.9)	44.3 (8.4)	42.3 (8.8)
12 wk	45.5 (10.3)	47.1 (8.2)	49.6 (8.5)	47.5 (8.5)	1.0 (0.3, 1.6)^{^*}	1.2 (−0.8, 3.3)	3.5 (1.3, 5.7)^{^*}	2.4 (0.3, 4.6)
24 wk	50.0 (11.1)	50.5 (10.1)	51.4 (9.1)	50.9 (9.4)	0.5 (−0.3, 1.2)	0.0 (−2.3, 2.4)	0.8 (−1.6, 3.2)	1.3 (−1.1, 3.6)
39 wk	50.6 (11.5)	51.1 (10.3)	52.7 (9.6)	51.8 (9.3)	0.6 (−0.2, 1.4)	0.1 (−2.3, 2.4)	1.5 (−0.9, 4.0)	1.6 (−0.9, 4.0)
52 wk	50.7 (12.0)	50.8 (11.0)	52.6 (10.3)	52.5 (8.5)	0.8 (0.1, 1.6)	0.3 (−2.7, 2.1)	1.4 (−1.2, 4.0)	2.2 (−0.2, 4.5)

SF-12 mental health component
0 wk	50.2 (10.5)	48.6 (10.5)	47.6 (11.2)	49.4 (9.6)
12 wk	50.2 (10.8)	50.4 (9.4)	47.8 (11.0)	48.0 (9.8)	−0.7 (−1.3, −0.0)	1.3 (−0.7, 3.3)	−0.5 (−2.6, 1.5)	−1.5 (−3.5, 0.4)
24 wk	51.8 (10.9)	52.8 (10.2)	50.8 (11.8)	51.3 (11.2)	−0.1 (−0.8, 0.6)	2.1 (−0.0, 4.2)	0.7 (−1.3, 2.8)	0.1 (−2.1, 2.2)
39 wk	51.7 (11.3)	51.5 (11.6)	49.2 (13.6)	49.0 (11.7)	−0.8 (−1.5, −0.0)	1.1 (−1.3, 3.4)	−0.4 (−2.9, 2.1)	−2.0 (−4.3, 0.3)
52 wk	51.3 (12.0)	50.4 (11.4)	50.6 (12.7)	50.4 (11.7)	−0.0 (−0.8, 0.8)	0.2 (−2.3, 2.7)	1.1 (−1.6, 3.7)	−0.3 (−2.9, 2.3)

EuroQol Health State (0-100 scale)
0 wk	70.1 (17.2)	72.1 (13.8)	73.5 (14.4)	68.2 (17.4)
12 wk	73.5 (17.3)	78.4 (14.1)	77.9 (15.0)	75.7 (14.5)	0.8 (−0.4, 2.0)	3.9 (0.0, 7.7)	2.7 (−1.3, 6.7)	3.1 (−0.8, 6.9)
24 wk	73.9 (17.5)	77.8 (15.5)	77.0 (15.4)	74.5 (16.7)	0.3 (−1.0, 1.6)	2.9 (−1.0, 6.9)	1.4 (−2.6, 5.5)	1.5 (−2.7, 5.8)
39 wk	73.1 (20.0)	76.8 (17.2)	76.6 (15.6)	75.3 (16.8)	0.9 (−0.5, 2.3)	2.6 (−1.9, 7.0)	1.8 (−2.6, 6.2)	3.2 (−1.3, 7.6)
52 wk	74.8 (17.0)	77.1 (17.0)	77.3 (15.3)	77.2 (14.9)	1.0 (−0.3, 2.2)	1.3 (−2.7, 5.4)	0.9 (−3.1, 4.9)	3.3 (−0.5, 7.2)

Non-prescription medication (times in last 4 wk)
0 wk	7.6 (10.0)	8.9 (10.8)	9.5 (10.0)	7.6 (9.4)
6 wk	4.3 (6.8)	4.1 (6.9)	4.0 (6.7)	4.0 (8.3)	0.1 (−0.5, 0.7)	0.6 (−1.2, 2.4)	0.9 (−0.8, 2.6)	0.3 (−1.5, 2.1)
12 wk	7.8 (11.0)	7.1 (23.0)	5.8 (7.6)	7.8 (25.8)	0.1 (−1.6, 1.8)	1.4 (−2.7, 5.6)	3.2 (0.4, 5.9)^{^*}	−0.1 (−5.5, 5.3)
18 wk	5.7 (7.4)	6.0 (10.4)	5.3 (9.1)	5.5 (9.1)	0.2 (−0.5, 0.8)	0.1 (−2.4, 2.6)	1.0 (−1.1, 3.2)	0.2 (−1.8, 2.2)
24 wk	8.1 (13.7)	7.7 (15.8)	6.5 (8.6)	6.4 (10.8)	0.7 (−0.4, 1.7)	0.9 (−3.3, 5.1)	2.4 (−0.7, 5.5)	1.8 (−1.5, 5.0)
39 wk	7.2 (14.2)	7.4 (12.2)	6.6 (8.9)	7.7 (13.5)	−0.0 (−1.1, 1.1)	0.3 (−3.4, 4.0)	1.4 (−1.9, 4.7)	−0.5 (−4.0, 3.1)
52 wk	6.5 (8.0)	6.6 (13.7)	6.7 (9.3)	6.8 (12.7)	−0.1 (−0.9, 0.8)	0.3 (−2.7, 3.4)	0.6 (−1.5, 2.6)	−0.3 (−2.9, 2.4)

SMT, spinal manipulative therapy group.

Unadjusted group means are from original data without imputation; slopes and group differences are computed from imputed data adjusted for the baseline covariates. Positive signs of slopes and mean differences were computed to favor higher doses of SMT.

^*P < .025

^†Likert scale: much worse = 1, worse = 2, about the same = 3, better = 4, much better = 5, and completely recovered = 6.