Statistical Analysis
depression, depressive, anxiety, trauma
REGRESSION
Data were analyzed from July 6, 2020, to September 21, 2022. We conducted our analyses using SAS, version 9.4 (SAS Institute Inc). Intention-to-treat analyses compared differences in outcomes across treatment groups. For depression and anxiety, we conducted direct comparisons of symptom episodes at each time point and examined symptom trajectories using treatment × time interactions. We used negative binomial regression to compare the incident rates of symptomatic episodes over 12 months of follow-up. Incident rates were calculated as the number of times an individual exceeded a symptom threshold divided by the number of assessments; we used an offset to standardize rates according to the number of assessments completed. An episode was defined as any follow-up time point at which a study participant scored over a designated threshold. Consistent with prior work,To examine symptom trajectories, we used generalized estimating equations to examine group × time effects on mean depressive and anxiety symptom scores. Consistent with prior work,To assess engagement and retention in care, we conducted direct comparisons at each time point. We conducted serial cross-sectional comparisons in which engagement or retention at each time point was considered independently. We also examined engagement as a cumulative phenomenon, such that anyone engaged with care at a proximal time point was considered engaged thereafter. We used logistic regression to compare the proportion of participants who met the definition of engagement, retention, or receipt of evidence-based care over the full follow-up period and adjusted models for whether participants had engaged with mental health care in the 6 months prior to enrollment.We examined heterogeneity of treatment effect according to whether participants were recruited during pregnancy or post partum and according to whether participants had a history of trauma. Because of our low rate of missing data overall and at each follow-up time point (