Factor structure, measurement invariance, and scoring practices of the strengths and weaknesses of ADHD–symptoms and normal behavior.

Abstract

We investigate the factor structure, concurrent validity, internal consistency, measurement invariance (sex and parents’ geographical/cultural background), and practical scoring practices of the Strengths and Weaknesses of Attention-deficit/Hyperactivity Disorder (ADHD)–Symptoms and Normal Behavior scale (SWAN) in junior high school students. With a sample of 650 parents of Mexican junior high school students (55.84% girls; mean age of 13.15 and SD = 0.97 years) who completed the SWAN scale, a bidirectional instrument, and the Barrios and Matute Questionnaire of ADHD symptoms (BMQ-ADHD), a traditional Mexican unidirectional instrument, we obtained SWAN’ psychometric properties by a series of confirmatory factor analyses. Two and three-correlated factors of the SWAN and bifactor models fitted well to the data. The bifactor model with one general dimension and two specific dimensions (BF 2S) showed most favorable psychometric properties and was invariant regarding sex and cultural background. The analyses of the BF 2S revealed that only the general factor was sufficiently reliable for scoring. Percentiles divided by sex better approximated SWAN averaged-based scores to the general factor derived from the SWAN bifactor model, measuring the trait with acceptable precision for norms development. The study provides evidence that SWAN measures a trait best represented by a reliable general domain, that the average-based SWAN score is closer to the general SWAN trait when the score is segregated by sex, and that it is invariant with respect to sex and cultural background to be reliable in a culturally diverse population.

Psychometric properties of the self-report version of the Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale in a sample of Hungarian adolescents and young adults

“…In studies on the parent- and teacher-report versions, exploratory factor analysis resulted in a two-factor structure (inattention and hyperactivity/impulsivity) in different samples ( 20 , 31 ). In studies using confirmatory factor analysis ( 31 , 35 , 51 , 52 ), bifactor models were reported to have a better fit than non-hierarchical models; however, similar to studies with other measures, the results suggested a strong and reliable general ADHD factor but mostly weak or unreliable specific factors. A single study under peer review ( 38 ) reported similar results for the new self-report version of the SWAN.…”

“…Symptoms of inattention are more likely to be present than hyperactive symptoms in women, sometimes leading to delayed referral and diagnosis ( 77 , 78 ). However, factor analytic studies reported gender invariance in adolescent ( 40 ) and adult ( 35 ) samples, suggesting that gender differences might not have a substantial influence on the results. On the other hand, cultural differences have been reported in the structure of ADHD symptoms; more research is needed in different cultural contexts ( 79 ).…”

“…Also, several empirical studies using parent or teacher-report versions of the SWAN scale have demonstrated the merits of this approach [e.g ( 30 , 67 ). ( 31 , 34 , 33 ) ( 35 – 37 )]. Up to now, there was no self-report instrument available that would measure both strengths and weaknesses in attention, activity, and impulse control.…”