Table 2.

Univariable Associations of Changes in Each Potential Mediator With Change in Functional Outcomes in STarT Back Participants: Linear Regression Analyses

Outcome	Predictor	Treatment Allocation	Change at 4-Month Follow-Up
			Unstandardized B (Standard Error)	95% CI	Standardized β	R2 Change
RMDQΔ	Catastrophizing thoughtsΔ	Treatment (n = 93)	.49 (.09)	.31–.67	.50	.25
	Fear-avoidance beliefsΔ		.57 (.09)	.40–.74	.57	.33
	AnxietyΔ		.59 (.09)	.40–.77	.56	.31
	DepressionΔ		.66 (.09)	.48–.83	.62	.39
	Least painΔ		.77 (.08)	.62–.93	.72	.51
	Average painΔ		.77 (.07)	.63–.91	.74	.55
	Current painΔ		.84 (.07)	.71–.98	.80	.63
	Catastrophizing thoughtsΔ	Control (n = 45)	.58 (.11)	.37–.80	.64	.41
	Fear-avoidance beliefsΔ		.73 (.12)	.05–.97	.67	.45
	AnxietyΔ		.46 (.10)	.27–.65	.59	.35
	DepressionΔ		.58 (.09)	.40–.75	.71	.50
	Least painΔ		.45 (.10)	.26–.65	.59	.34
	Average painΔ		.50 (.11)	.28–.72	.57	.32
	Current painΔ		.47 (.10)	.27–.68	.58	.34

NOTE. ^Δindicates residualized change.