Evaluating the Structure of Sluggish Cognitive Tempo Using Confirmatory Factor Analytic and Bifactor Modeling With Parent and Youth Ratings

The primary goals of this study were to evaluate the dimensionality of the Penny et al. Sluggish Cognitive Tempo Scale and to compare model fits for parent- and youth self-report versions. Participants were 262 young adolescents (ages 10-15) comprehensively diagnosed with attention-deficit/hyperactivity disorder. Both confirmatory factor analysis (CFA) and bifactor modeling were used to determine if the proposed three-factor structure previously identified through exploratory factor analysis could be confirmed. Results showed that although the three-factor CFA had better fit statistics than a one- or two-factor CFA, the bifactor model was the best-fitting model for both parent report and self-report. This implies that Sluggish Cognitive Tempo Scale is best conceptualized as having an underlying general factor, with three specific factors that may represent different etiologies. Importantly, results also showed low-to-moderate correlations between raters and equivalent or better fit statistics for self-report in comparison with parent report.