The Discrepancy between Performance-Based Measures and Questionnaires when Assessing Clinical Outcomes and Quality of...

In clinical outcome assessment, the relation between performance-based measures and questionnaire ratings of the same domain is weak, but correlations between questionnaires proposed for the evaluation of different domains are strong. The present study aims to illustrate these phenomena in a group of patients with neurofibromatosis type 1 (NF1) and to propose an explanatory hypothesis. A single neuropsychologist interviewed the parents about the child's situation and current difficulties and then assessed this parental view as overall positive or overall negative. The same assessor then administered the Wechsler Intelligence Scales and neuropsychological tests to 78 children and adolescents with NF1 (5-18 years). Parents then completed the Child Behavioral Checklist (CBCL), the Conners' Parent Rating Scale, the Behavior Rating Inventory of Executive Function (BRIEF), as well as questionnaires assessing quality of life, impact of the medical disorder, and their own difficulties. All questionnaires were inter-correlated (r = 0.29 - 0.84) and associated with the overall positive or negative parental view of the child's progress (effect size = 0.41-1.46). Conversely, questionnaires were weakly or not significantly related to intelligence, cognitive measures, or clinical severity. In conclusion, the parental view of the child's progress was related to the answers to questionnaires assessing quality of life or strengths and difficulties of patients with a neurological disorder. This factor should be assessed independently and taken into account when assessing clinical outcome.