Report of an initial pilot study on the feasibility of using the MacArthur competence assessment tool for clinical research in children and adolescents with attention-deficit/hyperactivity disorder.

INTRODUCTION

The MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR) was used in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) and co-morbid oppositional defiant disorder (ODD) and in their parents. The aims were to test feasibility and to determine children's understanding of the elements of disclosure for a clinical drug trial and their competence to assent.

METHOD

The contents and language of MacCAT-CR were adapted to be age appropriate for the children. Twelve children (mean age, 9.87 [7.7-12.2]; mean intelligence quotient [IQ], 97 [72-122]) and either the mother or father of each child were interviewed. Psychologists rated the interviews and, in addition to MacCAT-CR, competence was assessed by trained clinicians.

RESULTS

The MacCAT-CR was practicable, and the time required was acceptable. Interrater reliability was excellent in children. Children performed less well than parents on this test (children;s vs. parents' scores: Understanding 5.86 vs. 9.08, appreciation 2.64 vs. 4.96, reasoning 3.05 vs. 4.63, respectively). Whereas clinicians assessed all children as competent, lack of competence became apparent in the MacCAT-CR.

CONCLUSIONS

The practicability and the interrater reliability suggest that the MacCAT-CR is feasible in children, but the question of whether competence is assessed validly remains unsolved in the absence of external validation. The differences between assessment by clinicians and the low scores obtained in the MacCAT-CR suggest that children may give assent even if they do not understand completely. The results of this initial pilot study may help in the planning of further investigations intended to improve information about studies and assessment of assent/consent.