Concordance and validity between versions of the ADHD Conners scale for Parents

The Conners Scale for Parents (CRS-P) is one of the reference tools for the diagnostic assessment of Attention Deficit and Hyperactivity Disorders (ADHD). It is commonly used in both research and clinical practice. The latest edition of the Conners Parents Scale Long Version (CRS-P3L) has undergone extensive modifications but has never been compared with the 2nd edition (CRS-P2L). We aim to study the concordance between the last two editions of the CRS-P, their internal consistency, and their validity against the criteria of the ADHD-RS.

The study population was a cohort of 30 children diagnosed with ADHD participating in a clinical trial. The parents of these children completed both editions of the CRS (P2L and P3L), as well as a DSM-IV ADHD Diagnostic Criteria Rating Scale (ADHD-RS). A linear regression model with the calculation of Lin's concordance coefficient (LCC) was used to study the concordance between the scales. Internal validity was estimated with Cronbach's alpha and inter-criteria validity with Spearman's correlation coefficient.

The internal consistency found was "correct" to "good" for both editions (Cronbach alpha 0.85 and 0.77), their correlation with the ADHD-RS was medium to low (Spearman's coefficient 0.25 and 0.09). Concordance between the overall score and the sub-scores of the two editions of the same Conners scale (CRS-P2L and CRS-P3L) was fair to medium (LCC 0.29 to 0.69).

The third edition of the long version of the CRS-P showed very poor concordance with the previous edition. The diagnostic profile of the children seems to have evolved with the new edition, which appears to affect the interpretation of the tests.