Table 4.

Best-fitting linear mixed models of time in moderate-to-vigorous physical activity in patients with chronic spinal pain and comorbid insomnia, constructed with the aim to explore determinants for a change in MVPA in response to physical therapy treatment.

MVPA models	Main effects		Model with interactions
	Estimate (SE)	P value	Estimate (SE)	P value
Final model including control variables
Sex (Male)	-4.6 (2.1)	.03*	-4.5 (2.1)	.03*
Age	-0.0 (0.1)	.71	-0.0 (0.1)	.69
Education		.62		.20
Lower	-1.7 (2.7)		-7.4 (4.2)
Bachelor	0.9 (2.1)		-4.2 (3.3)
Master or higher	(reference)		(reference)
Allocation	-1.1 (1.9)	.55	-1.1 (1.9)	.56
Time	0.1 (0.8)	.87	-2.2 (1.3)	.85/.10
Pain duration	0.9 (1.0)	.33	1.0 (1.0)	.30
Education $\times$ time				.10
Lower			3.7 (2.2)
Bachelor			3.3 (1.7)
Master or higher			(reference)
Final model after removal of the worst fitting variables
Sex (Male)	-4.5 (2.0)	.03*	-4.5 (2.0)	.03*
Education		.54		.17
Lower	-2.0 (2.6)		-7.6 (4.2)
Bachelor	0.8 (2.1)		-4.3 (3.3)
Master or higher	(reference)		(reference)
Time	0.1 (0.8)	.86	-2.2 (1.3)	.85/.10
Pain duration	0.8 (0.9)	.37	0.8 (0.9)	.35
Education $\times$ time				.10
Lower			3.7 (2.2)
Bachelor			3.3 (1.7)
Master or higher			(reference)

Estimates are unstandardized. MVPA, moderate to vigorous physical activity; SE, standard error.

^⁎p < .05.