Abstract
Machine Learning (ML) is a promising approach for predicting outcomes of youth anxiety treatments. To this end, data from nine randomized controlled trials of youth anxiety treatments were concatenated into a dataset (N = 1362; M(age) = 10.59, SD(age) = 2.47; 48.9% female; 71.9% White, 5.9% Black, Other, 5.9%; 10.8% Hispanic) and ML algorithms were used to predict outcomes. Models were then applied on an external validation sample in a research clinic (N = 50; M(age) = 12.04, SD(age) = 3.22; 56% female; 76% Caucasian, 10% Black, 6% Asian, 2% Other; 6% Hispanic). To examine predictive features by treatment type, Lasso Regression models were built separately for youth who completed individual cognitive behavioral therapy (CBT), family CBT (FCBT), sertraline alone (SRT), and combination of SRT and CBT (COMB). Automatic relevance determination (ARD) emerged as the best performing model in the concatenated (RMSE = 1.84, R(2) = 0.28) and external validation datasets (RMSE = 1.87, R(2) = 0.11). Predictive features of poorer outcomes were primarily indicators of symptom severity and trial effects, although predictors varied within treatments (e.g., caregiver psychopathology was predictive for FCBT; depressive symptoms were predictive for COMB). Implications for use of ML to predict outcomes are discussed.