Disentangling symptoms of externalizing disorders in children using multiple measures and informants.

The trait impulsivity theory suggests that a single, highly heritable externalizing liability factor, expressed as temperamental trait impulsivity, represents the core vulnerability for externalizing disorders. The present study sought to test the application of latent factor models derived from this theory to a clinical sample of children. Participants were 474 German children (age 6-12 years, 81% male) with symptoms of attention-deficit/hyperactivity disorder and externalizing behavior problems participating in an ongoing multicenter intervention study. Using confirmatory factor analyses (CFA) and exploratory structural equation modeling (ESEM), we evaluated several factor models of externalizing spectrum disorders (unidimensional; first-order correlated factors; higher-order factor; fully symmetrical bifactor; bifactor S-1 model). Furthermore, we assessed our prevailing factor models for measurement invariance across raters (clinicians, parents, teachers) and assessment modes (interview, questionnaires). While both CFA and ESEM approaches provided valuable insights into the multidimensionality, ESEM solutions were generally superior since they showed a substantially better model fit and less biased factor loadings. Among the models tested, the bifactor S-1 CFA/ESEM models, with a general hyperactivity-impulsivity reference factor, displayed a statistically sound factor structure and allowed for straightforward interpretability. Furthermore, these models showed the same organization of factors and loading patterns, but not equivalent item thresholds across raters and assessment modes, highlighting cross-situational variability in child behavior. Our findings are consistent with the assumption of the trait impulsivity theory that a common trait, presented as hyperactivity-impulsivity symptoms, underlies all externalizing disorders. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Toward a Dimensional Assessment of Externalizing Disorders in Children: Reliability and Validity of a Semi-Structured Parent Interview.

OBJECTIVE: This study assesses the reliability and validity of the DSM-5-based, semi-structured Clinical Parent Interview for Externalizing Disorders in Children and Adolescents (ILF-EXTERNAL). METHOD: Participant data were drawn from the ongoing ESCAschool intervention study. The ILF-EXTERNAL was evaluated in a clinical sample of 474 children and adolescents (aged 6-12 years, 92 females) with symptoms of attention-deficit/hyperactivity disorder (ADHD). To obtain interrater reliability, the one-way random-effects, absolute agreement models of the intraclass correlation (ICC) for single ICC(1,1) and average measurements ICC(1,3) were computed between the interviewers and two independent raters for 45 randomly selected interviews involving ten interviewers. Overall agreement on DSM-5 diagnoses was assessed using Fleiss' kappa. Further analyses evaluated internal consistencies, item-total correlations as well as correlations between symptom severity and the degree of functional impairment. Additionally, parents completed the German version of the Child Behavior Checklist (CBCL) and two DSM-5-based parent questionnaires for the assessment of ADHD symptoms and symptoms of disruptive behavior disorders (FBB-ADHS; FBB-SSV), which were used to evaluate convergent and divergent validity. RESULTS: ICC coefficients demonstrated very good to excellent interrater reliability on the item and scale level of the ILF-EXTERNAL [scale level: ICC(1,1) = 0.83-0.95; ICC(1,3) = 0.94-0.98]. Overall kappa agreement on DSM-5 diagnoses was substantial to almost perfect for most disorders (0.38 ≤ κ ≤ 0.94). With some exceptions, internal consistencies (0.60 ≤ α ≤ 0.86) and item-total correlations (0.21 ≤ r it ≤ 0.71) were generally satisfactory to good. Furthermore, higher symptom severity was associated with a higher degree of functional impairment. The evaluation of convergent validity revealed positive results regarding clinical judgment and parent ratings (FBB-ADHS; FBB-SSV). Correlations between the ILF-EXTERNAL scales and the CBCL Externalizing Problems were moderate to high. Finally, the ILF-EXTERNAL scales were significantly more strongly associated with the CBCL Externalizing Problems than with the Internalizing Problems, indicating divergent validity. CONCLUSION: In clinically referred, school-age children, the ILF-EXTERNAL demonstrates sound psychometric properties. The ILF-EXTERNAL is a promising clinical interview and contributes to high-quality diagnostics of externalizing disorders in children and adolescents.