Table 3. Effect of the Intervention on Patients’ Symptoms of Depression and Anxietya.
Outcome | Patients/Clinicians, No.b | Mean Value for Psychological Symptoms (95% CI) at Follow-upc | β (95% CI)d | P Value | |
---|---|---|---|---|---|
Control | Intervention | ||||
Depression Symptoms | |||||
3 Months after target visit | |||||
2-Indicator latent variablee,f | 262/113 | 0.20 (−0.02 to 0.42) | 0.26 (−0.04 to 0.55) | −0.10 (−0.33 to 0.12) | .37 |
Standard PHQ-8 composite scoreg,h | 359/119 | 4.88 (4.23 to 5.54) | 5.92 (5.19 to 6.66) | 0.26 (−0.57 to 1.10) | .54 |
6 Months after target visit | |||||
2-Indicator latent variablee,i | 262/113 | 0.24 (0.07 to 0.42) | 0.40 (0.11 to 0.69) | 0.21 (−0.04 to 0.46) | .11 |
Standard PHQ-8 Composite Scoreg,j | 314/118 | 4.84 (4.17 to 5.51) | 5.927 (5.05 to 6.81) | 0.45 (−0.48 to 1.37) | .34 |
Anxiety Symptoms | |||||
3 Months after target visit | |||||
2-Indicator latent variablee,h | 277/119 | 0.22 (0.01 to 0.43) | 0.28 (−0.04 to 0.60) | −0.03 (−0.23 to 0.16) | .73 |
Standard GAD-7 composite scoreh,k | 366/122 | 3.00 (2.44 to 3.57) | 3.26 (2.64 to 3.89) | 0.04 (−0.95 to 1.03) | .94 |
6 Months after target visit | |||||
2-Indicator latent variablee,h | 277/119 | 0.21 (−0.05 to 0.47) | 0.30 (0.00 to 0.59) | −0.04 (−0.25 to 0.16) | .69 |
Standard GAD-7 composite scoreh,k | 327/119 | 3.08 (2.44 to 3.72) | 3.375 (2.67 to 4.08) | −0.11 (−1.20 to 1.00) | .85 |
Abbreviations: CFA, confirmatory factor analysis; GAD-7, 7-item Generalized Anxiety Disorder survey; PHQ-8, 8-item Patient Health Questionnaire; WLSMV, weighted least squares with mean and variance adjustment.
The coefficient estimates and P values were based on complex single-group regression models with patients clustered by treating clinician, with intervention group as the predictor of interest, and with adjustment for any variables that confounded the association between the intervention-group predictor and outcome. A variable was identified as a confounder if its addition to the bivariate model changed the coefficient for the intervention group by 10% or more in either direction. For the latent variable outcomes, the sample included only those patients who provided data for both indicators at all 3 time points (baseline, 3-month follow-up, and 6-month follow-up). For all outcomes, patients were included only if they provided data for the outcome and any covariates in the model.
Number of patients/number of clinician clusters.
For the standard composite scores, the unadjusted mean for the standard composite score, computed with data from the follow-up questionnaire. For the 2-indicator constructs, the mean value of the construct on the follow-up questionnaire, based on a 2-group CFA model using patients with complete data for the 3 time periods, with scalar measurement invariance imposed between groups and over time, and with the baseline mean for the control group fixed at 0.
Point estimate and confidence interval for the regression coefficient from a single-group model with the outcome regressed on the intervention-group predictor, after adjustment for any confounders.
Probit regression model, estimated with WLSMV.
Adjusted for baseline level on the outcome and the patient’s racial/ethnic minority status.
Robust linear regression model, estimated with restricted maximum likelihood.
Adjusted for baseline level on the outcome.
Adjusted for patient’s baseline level on the outcome, age, racial/ethnic minority status, education, and self-identified health status; and for clinician type and specialty.
Adjusted for patient’s baseline level on the outcome and clinician specialty.
The outcome was defined as censored from below; Tobit regression model estimated with WLSMV.