ABSTRACT
This study examines the impact of interrater reliability on the diagnosis of attention-deficit hyperactivity disorder (ADHD). A screening of 6171 elementary school children identified 1573 children with a high risk for ADHD according to teacher rating. Follow-up parent interviews and information from teachers were collected on 243 children. Before screening, health care professionals had diagnosed ADHD in 40% of the identified children. There was low agreement between the parent and teacher reports of ADHD symptoms according to DSM-IV-based questionnaires: Inattentive (r =.34, kappa = 0.27), Hyperactive/Impulsive (r =.27, kappa = 0.22), and Performance Impairment (r =.31, kappa = 0.07). When the two-setting requirement was strictly enforced, poor interrater agreement decreased diagnostic rates for all three types of ADHD in this clinical sample: Inattentive (15%-5%), Hyperactive/Impulsive (11%-3%), and Combined (23%-7%). Parent and teacher agreement was low concerning ADHD symptoms and performance. The recommendation of multiple informants significantly decreased the prevalence. Allowing for observer disagreement by using more lenient core symptom scores could reduce the effect.
