BACKGROUND
There is a huge variability in the way individuals with tinnitus respond to interventions. These experiential variations together with a range of associated etiologies, contribute to tinnitus being a highly heterogeneous condition. Despite this heterogeneity, a “one size fits all” approach is taken when making management recommendations. Although there are various management approaches, not all are equally effective. Psychological approaches such as cognitive behavioral therapy (CBT) have the most evidence-base.
OBJECTIVE
Managing tinnitus is challenging due to the significant variations in tinnitus experiences and treatment success. Tailored interventions based on individual tinnitus profiles may improve outcomes. Predictive models of treatment success are, however, lacking. The current study aimed to used exploratory data mining techniques (i.e., decision tree models) to identify the variables associated with treatment success for an Internet-based cognitive behavioral therapy (ICBT) for tinnitus.
METHODS
Individuals (n = 228) who underwent ICBT in three separate clinical trials were included in this analysis. The primary outcome variable was reducing 13 points in tinnitus severity as measured by the Tinnitus Functional Index following the intervention. Predictor variables included demographic characteristics, tinnitus, and hearing-related variables, and clinical factors (i.e., anxiety, depression, insomnia, hyperacusis, hearing disability, cognitive function, and life satisfaction). Analyses were undertaken using various exploratory machine learning algorithms to identify the most suitable variable. Five decision tree models were implemented, namely CART, C5.0, Gradient Boosting, AdaBoost algorithm, and Random Forest. The SHapley Additive exPlanations (SHAP) framework was applied to the two best models to identify the relative predictor importance.
RESULTS
Of the five decision tree models, CART (accuracy of 74%, sensitivity of 74%, specificity of 64%, and AUC .69) and Gradient boosting (accuracy of 72%, sensitivity of 78%, specificity of 59%, and area under the curve .68) were found to be the best predictive models. Although the other models had an acceptable accuracy (ranged between 56 to 66%) and sensitivity (varied between 69 to 75%), they all had relatively weak specificity (varied between 31 to 50%) and area under the curve (varied between .52 to .6). Higher baseline tinnitus severity and higher education level were the most influencing factors in the ICBT outcome. The CART decision tree model identified three participant groups who had at least 85% success probability following undertaking ICBT.
CONCLUSIONS
In this study, decision tree models, especially the CART and Gradient boosting models, appear to be promising in predicting the ICBT outcomes. Their predictive power may be improved by using larger sample sizes and including a wider range of predictive factors in future studies.
Exploratory data mining to examine the impact of internet-based cognitive behavioral therapy for tinnitus: Application of decision tree models (Preprint)