Attention Deficit Hyperactivity Disorder: A Rasch Analysis of the SWAN Rating Scale

Abstract

The prevalence of attention-deficit/hyperactivity disorder (ADHD) has been estimated at 3-7% in the population. Children with this disorder are often characterized by symptoms of inattention and/or impulsivity and hyperactivity, which can significantly impact on many aspects of their behaviour and performance. This study investigated the characteristics of the SWAN Rating Scale and its discrimination of ADHD subtypes. This instrument was developed by Swanson and his colleagues and measures attentiveness and hyperactivity on a continuum, from attention problems to positive attention skills, using a seven-point scale of behaviour: "far below average" to "far above average". The Australian Twin Attention-Deficit/Hyperactivity Disorder Study consists of questionnaire data collected from families in 1990/2007. The Rasch model was used to measure the characteristics of items from the SWAN Rating Scale; how well these items discriminated between those with and without ADHD. The prevalence of each subtype was found to be 5.3% for inattentive ADHD, 4.3% for hyperactive ADHD and 4.6% for combined ADHD. A total of 14.2% of the cohort appeared to have ADHD. While the inattentive items appeared to be consistent with each other in their measurement behaviour and response patterns, the hyperactive items were less consistent. Further, the combined subtype appeared to be an entirely different type, with unique features unlike the other two subtypes. Further work is needed to distinguish the diagnostic features of each subtype of ADHD.

Inattention, working memory, and academic achievement in adolescents referred for attention deficit/hyperactivity disorder (ADHD)

“…Therefore, the higher the SWAN score, the more inattentive the teacher rated the adolescent. Previous research has demonstrated that the inattentiveness and hyperactivity/impulsivity items on the SWAN have strong cohesiveness (Young, Levy, Martin, & Hay, 2009) and they showed very good internal reliability within the current sample (r = .93 for inattentive scale, r = .95 for hyperactive/impulsive scale). letters that are read aloud by the examiner at a rate of one digit per second, starting with two digits/letters.…”

Working Memory With Emotional Distraction in Monolingual and Bilingual Children

“…Higher scores are indicative of better attentional abilities, lower hyperactivity, and lower impulsivity. The SWAN has excellent internal consistency and reliability (Young et al, 2009; Lakes et al, 2012). …”

Home environmental and behavioral risk indices for reading achievement

“…The Hyperactivity/impulsivity scale is comprised of 9 items (e.g., “Settles down and rests [controls constant activity]”), which are scored on the same 7-point scale described for the Inattention scale, with lower scores indicating increased symptoms of hyperactivity/impulsivity. Internal consistency of this scale is high in previous research (α = .94; Young et al, 2009). …”

“…All items are averaged to make a total Inattention symptoms score, with lower scores indicating more attention problems. The scale has been shown to demonstrate strong psychometric properties including good internal consistency (α = .94; Young, Levy, Martin, & Hay, 2009). The Hyperactivity/impulsivity scale is comprised of 9 items (e.g., “Settles down and rests [controls constant activity]”), which are scored on the same 7-point scale described for the Inattention scale, with lower scores indicating increased symptoms of hyperactivity/impulsivity.…”