Analysis of Intervention Effects
Anxiety
REGRESSION, DISORDER
Stata (version 17; StataCorp) [Treatment effects from preintervention to during-the-intervention, postintervention, and follow-up assessments were evaluated using a series of 1-tailed paired-sample Adjusted analysis of intervention effects was performed using mixed-effects linear regression models. We estimated both fixed and random effects to assess the intervention effects of time point and condition on the change in the 2 primary outcomes, GAD-7 and PHQ-9 scores. Both measures, GAD-7 and PHQ-9 in long format, were normally distributed, satisfying the assumption of the mixed-effects model. We also tested the interaction effects of time point and condition, but they were not significant; therefore, noninteractive models were assessed for both the GAD-7 and PHQ-9. The appropriateness of the mixed-effects model for each outcome was assessed by comparing each with the standard linear regression model and random-intercept linear model based on likelihood ratio tests with strong evidence (Trajectories of estimated mean 7-item Generalized Anxiety Disorder Scale (GAD-7) scores over time points by intervention conditions. DMH: digital mental health.Trajectories of estimated mean 9-item Patient Health Questionnaire (PHQ-9) scores over time points by intervention conditions. DMH: digital mental health.Reliable and clinically significant change in 7-item Generalized Anxiety Disorder Scale (GAD-7) score. (A) Change in GAD-7 scores from before to after treatment; (B) Change in GAD-7 scores from before treatment to follow-up.Reliable and clinically significant change in 9-item Patient Health Questionnaire (PHQ-9) score. (A) Change in PHQ-9 scores from before to after treatment; (B) Change in PHQ-9 scores from before treatment to follow-up.