Conners' rating scales in the assessment of attention deficit disorder with hyperactivity (ADHD). A new validation and factor analysis in Spanish children

The use of Conner's Rating Scales (CRS) is very extended for the assessment of attention deficit disorder with hyperactivity (ADD-H). The main objective of this work is to study the validity of construct of CRS from theoretical basis and data statistical analysis. The study is based on a control group of 633 children and a clinical group of 33 subjects. We used a Spanish version of the Conner's Teacher Rating Scale (CTRS) and Conner's Parents Rating Scale (CPRS) in both groups. From the analysis of scales contents we attribute the items to several behavioral areas and we performed a factorial analysis. Studies of reliability, external validity versus clinical criteria, and analysis of correlations between parents and teachers scales were also performed. Findings from factorial analysis and study of reliability have shown the questions of CTRS to be clustered in three well-defined and reliable factors: hyperactivity, attention deficit, and conduct disorder. The questions dealing with emotional disorders are not sufficiently consistent to constitute a separate factor. CPRS has a lower reliability than CTRS, and its factorial analysis does not allow to consider a factorial distribution. The validity is high in CTRS and no significative in CPRS. Correlation between scales is also low. As a consequence of these results we propose a Spanish experimental revised form of the CTRS, with 20 items. This new form can assess separately: attention deficit; hyperactivity and conduct disorder, according to the current clinical criteria of CIE-10 and DSM-IV.