. Author manuscript; available in PMC: 2016 Jan 11.

Published in final edited form as: Appl Ergon. 2011 Oct 24;43(4):639–644. doi: 10.1016/j.apergo.2011.09.010

Table 3.

Multi-level model including and excluding main effect parameters.

Variable	Model 1 (std. error)	Model 2 (std. error)
Chair comfort	−0.41 (0.09)^*	−0.34 (0.10)^*
Exercise due to pain	−0.31 (0.09)^*	−0.29 (0.09)^*
Strength of medications	0.20 (0.06)^*	0.19 (0.06)^*
β₁: Chair-and-training group	−0.26 (0.36)^ns	−0.05 (0.37)^ns
β₂: Training-only group	−0.03 (0.38)^ns	0.28 (0.40)^ns
β₃: Intervention phase	−0.44 (0.07)^*	−0.17 (0.11) ^ns
β₄: Chair-intervention	–	−0.40 (0.16)^*
β₅: Training-intervention	–	−0.53 (0.16)^*
β₀: Intercept term	3.68 (0.33)	3.36 (0.36)
ε_ij: Level 1 variance	2.95 (0.08)	2.94 (0.08)
μ_j: Level 2 variance	3.95 (0.43)	3.97 (0.43)
Model −2 ln (likelihood)	13526.02	13513.80
	Difference in −2 ln (likelihoods) = 12.22^*

= p<0.05;

^ns

= p> 0.05.