Parent SNAP‐IV rating of attention‐deficit/hyperactivity disorder: accuracy in a clinical sample of ADHD, validity, and reliability in a Brazilian sample

Abstract

ObjectiveTo investigate the psychometric properties of the short or multimodal treatment study version of the Swanson, Nolan, and Pelham, Version IV (SNAP‐IV) scale, which measures attention‐deficit/hyperactivity disorder and oppositional defiant disorder symptoms. MethodsParticipants were 765 parents of children from 4 to 16 years old (641 non‐attention‐deficit/hyperactivity disorder and 124 attention‐deficit/hyperactivity disorder children) from Belo Horizonte, Brazil, who reported sociodemographic characteristics and answered the SNAP‐IV. Parents of the clinical sample also underwent the K‐SADS‐PL interview. ResultsAge was significantly associated with SNAP‐IV hyperactivity‐impulsivity problems (r = −0.14), but not with inattention or oppositional defiant disorder. Sex was a significant influence on attention‐deficit/hyperactivity disorder and oppositional defiant disorder severity (all p <0.001), with boys showing higher scores in the full sample, but not within the attention‐deficit/hyperactivity disorder group. Exploratory and confirmatory factor analysis supports a three‐factor structure of the SNAP‐IV scale. Moderate‐to‐strong correlations were found between SNAP‐IV and K‐SADS‐PL measures. All SNAP‐IV scales showed very high internal consistency coefficients (all above 0.91). SNAP‐IV inattention scores were the most predictive of attention‐deficit/hyperactivity disorder diagnosis (AUC: 0.877 for the averaging rating method and the raw sum method, and 0.874 for the symptom presence/absence method). ConclusionThe parent SNAP‐IV showed good psychometric properties in a Brazilian school and clinical sample.