Effectiveness of an Integrated Care Pathway for Depression: Cluster Randomized Controlled Trial

Background: Depression is the leading cause of disability in adolescents and a potent risk factor for suicide. Evidence-based treatments are available; however, many clinics do not provide guidelines-based treatments. Integrated Care Pathways (ICPs) are treatment algorithms based on the highest quality practice guidelines intended to facilitate the delivery of evidence-based treatment at the clinic level. Our group has already tested the feasibility of ICP for adolescent depression at an academic setting. There is still uncertainty regarding whether ICPs lead to improved outcomes in depression in adolescents in community settings relative to typical care. Objective: The current study aim is to test the effectiveness of an ICP for depression in adolescence, called the CARIBOU-2 intervention, versus treatment-as-usual (TAU) in community settings. This study will also examine important implementation outcomes. Method: The primary participants are adolescents (Up to N=150), between the ages of 13 to 18 with depressive symptoms, presenting to one of the participating sites. Through a quasi-experimental, multi-site cluster controlled clinical trial design, sites began in the TAU condition and transitioned to the ICP condition once local enrollment to TAU has reached up to 25 participants. The primary clinical outcome of interest is the difference between treatment groups in the rate of change of depressive symptoms from baseline to 24-week endpoint as measured by the Mood and Feelings Questionnaire. Secondary outcomes include rate of change of functional improvement, as measured by the Childhood Anxiety and Depression Life Interference Scale, and caregiver-rated internalizing symptoms as rated by the Childhood Behaviour Checklist. This study will also be examining the following implementation outcomes: feasibility, fidelity cost and acceptability. Implementation will also be assessed at three additional sites through a light-touch evaluation conducted several months after training and implementation of the pathway, focusing on clinicians' perspectives and experiences. Statistical Analyses: Descriptive data analysis will be first conducted to examine distribution of collected measures and evaluate whether there are significant differences across arms of assigned sites. Generalized linear mixed-effects model will be the primary analytic tool for evaluating whether the CARIBOU-2 intervention is more effective than TAU for adolescents with depression presenting to care with regards to improvement of depressive symptoms, self-reported functioning, caregiver-reported internalizing psychopathology, and suicidal ideation and behaviours. Time, treatment assignment and their interactions will serve as the primary predictors for the analyses. As an example, if we let Y\_ijt to denote a continuous outcome of the j-th participant of the i-th site measured at time t, a linear model for Y\_ijt will look like the following: Y\_ijt=β\_0+〖b\_(0,ij)+b\_(1,i)+β〗\_1 t+β\_2 〖Group〗\_(i,t)+β\_3 Group\_it\*t+〖β\_4 X\_ijt+ϵ〗\_ijt of which 〖Group〗\_(i,t) denotes the treatment assignment of the i-th site at time t, X\_ijt, additional covariates, b\_(0,ij) and b\_(1,i), random effects at individual and site levels respectively, ϵ\_( ijt), unexplained random error, and β's, regression coefficients. For sensitivity analyses, we will explore the use of the piecewise model to model the time trend differently. We will adopt the intention-to-treat approach in general and use multiple imputation methods as the primary missing data strategy. In our pilot study, we have collected \~85% of expected longitudinal data points on the MFQ (primary clinical outcome), adjusting for attrition. Sensitivity analysis will be conducted to evaluate the impact of non-random missing and robust regression method will be used instead when the impact is high. SAS 9.4 will be our go-to software package for this project. Relevance: Should our results be consistent with our hypotheses, systematic implementation of the CARIBOU-2 intervention to other community mental health agencies and hospitals would be indicated.