Table 5.

Results of functions of time on stress levels over six months.

Model			1		2		3		4
Treatment effects			Est	SE	Est	SE	Est	SE	Est	SE
Fixed effects
	Intercept		6.31d	0.19	6.70d	0.22	6.98d	0.26	7.20d	0.26
	Lineara				–0.18d	0.05	–0.60d	0.22	–2.49d	0.66
	Quadraticb						0.07d	0.03	1.37d	0.43
	Cubicc								–0.17d	0.05
Random effects
	σ2 within participants		10.89d	0.60	10.75d	0.61	10.66d	0.61	10.44d	0.58
	σ2 between participants		5.68d	0.79
		Intercept			6.46d	1.08	6.92d	1.09	7.05d	1.08
		Intercept, slope			–0.21	0.16	–0.28	0.15	–0.31d	0.14
		Slope			0.00	0.00	0.01	0.00	0.01	0.00
Model fit indexes
	AIC		5708.19		5693.92		5692.41		5686.56
	–2LL (χ2)		5702.19		5681.92		5678.41		5670.56
	R 2 (level 1)				0.01		0.02		0.04

^aLinear: 0 = baseline, 1 = 1 month, 2 = 2 months, 6 = 6 months.

^bQuadratic: 0 = baseline, 1 = 1 month, 4 = 2 months, 36 = 6 months.

^cCubic: 0 = baseline, 1 = 1 month, 8 = 2 months, 216 = 6 months.

^d P<.05.