Table 2.

Secondary Analysis: Unmatched Treatment Groups—Outcomes after RCT

Outcome Measures	Pre-Post	Unmatched Treatment		Group Effect	Interaction	Time Effect (n=82 with
		Groups		(F df)	(F df)	complete data)
						(F df)
		Opposite	EBC			Intention to Treat* (n=96)
		Mean	Mean			(F df)
		(SD)	(SD)
Back pain/10	Pre	6.04	5.78	0.01 1,80 (p=0.98)	1.31 1,80 (p=0.26)	10.88 1,80 (p=0.001)
		(2.22)	(2.02)			101.72 1,94 (p<0.001)
	Post	5.09	5.33
		(2.28)	(2.18)
Leg pain/10**	Pre	3.66	2.75	0.70 1,75 (p=0.42)	1.42 1,75 (p=0.24)	0.02 1,75 (p=0.90)
		(3.23)	(3.04)			0.039 1,93 (p=0.94)
	Post	3.27	3.11
		(2.95)	(3.21)
RMDQ: Total yes/24	Pre	15.61	19.65	8.36 1,78 (p<0.001)	1.03 1,78 (p=0.31)	2.76 1,78 (p=0.10)
		(6.16)	(4.21)			2.70 1,94 (p=0.10)
Post	15.09	17.76
	(6.75)	(5.90)
Medication: Total	Pre	3.50	2.73	0.65 1,29 (p=0.43)	0.12 1,29 (p=0.73)	4.30 1,29 (p=0.047)
pills/day**		(2.90)	(2.02)			0.050 1,48 (p=0.82)
	Post	2.56	2.06
		(2.76)	(1.83)
During the past week,	Pre	3.37	3.34	0.42 1,79 (p=0.66)	1.65 1,79 (p=0.20)	2.17 1,79 (p=0.15)
pain interference		(1.06)	(0.91)			4.461 1,94 (p=0.037)
with usual work,	Post	3.13	3.34
in and outside		(1.09)	(0.97)
home: rating (0–5)
BDI-11/63	Pre	7.31	6.50	0.70 1,74 (p=0.41)	1.19 1,74 (p=0.28)	13.97 1,78 (p<0.001)
		(7.24)	(6.33)			25.10 1,94 (p<0.001)
	Post	6.31	4.71
		(7.16)	(4.17)
Taking medication (Yes)	Pre	12	8	McNemar test used for time effect (p=0.63)
		(63.2%)	(66.7%)	Groups collapsed due to small n (p=0.55)
	Post	10	8
		(52.6%)	(66.7%)

Opposite = evidence-based advice and exercises opposite to direction preference; EBC = evidence-based advice and common back exercises with no directional preference; RMDQ = Roland Morris Disability Questionnaire; BDI = Beck Depression Inventory

*Intention-to-treat analysis using carry-forward of last known data point

**Floor effect: those with no leg pain/no medication at baseline were excluded from analysis.