Table 7.

Final combined mixed effects model predicting Patient Health Questionnaire (PHQ-8) score change^a.

			Estimate		SE		P value
Intercept			15.36		0.14		<.001
Week			−1.10		0.04		<.001
Week2			0.06		0.002		<.001
Associate’s or bachelor’s degree or higher (ref=high school)			−0.18		0.12		.120
Associate’s degree or higher × week (ref=high school)			−0.07		0.02		.002
Age (years, ref=18-25)
	26-35	−0.16		0.13		.20
	36-49	−0.10		0.16		.52
	>50	−0.41		0.26		.12
Age (years, ref=18-25) × week
	26-35	−0.03		0.02		.15
	36-49	−0.01		0.03		.76
	>50	0.04		0.04		.32
Intake PHQ-8 score			3.73		0.06		<.001
Intake PHQ-8 score × week			−0.50		0.03		<.001
Intake PHQ-8 score × week2			0.03		0.002		<.001
First time in therapy			−0.07		0.13		.58
First time in therapy × week			−0.30		0.06		<.001
First time in therapy × week2			0.03		0.005		<.001

^aPredictor and predictor × time interaction variables that were significant in simpler models were included. The intake PHQ-8 scores were grand mean-centered.