Patient-Reported Pediatric Quality of Life Inventory™ 4.0 Generic Core Scales in Pediatric Patients with Attention-Deficit/Hyperactivity Disorder and Comorbid Psychiatric Disorders: Feasibility, Reliability, and Validity

Objectives: The primary objective of the study was to evaluate the feasibility, reliability, and validity of the Pediatric Quality of Life Inventory (TM) (PedsQL) 4.0 Generic Core Scales as a patient self-reported health-related quality of life measurement instrument in pediatric patients with attention-deficit/hyperactivity disorder (ADHD) and physician-diagnosed comorbid psychiatric disorders being seen in a pediatric psychiatric clinic. The secondary objective was to evaluate parent proxy-reported PedsQL in this population. Methods: One hundred seventy-nine children with ADHD and comorbid psychiatric disorders ages 5 to 18 years and 181 parents completed the PedsQL 4.0 Generic Core Scales and parents also completed the Vanderbilt ADHD Diagnostic Rating Scales. Known-groups discriminant validity comparisons were made between the sample of pediatric patients with ADHD and comorbid psychiatric disorders and healthy, cancer, and type 1 diabetes samples. Results: The PedsQL evidenced minimal missing responses for patient self-report and parent proxy-report (0.2% and 0.5%, respectively), demonstrated no significant floor or ceiling effects, and achieved excellent reliability for the Total Scale Score (alpha = 0.85 patient self-report, 0.92 parent proxy-report). Pediatric patients with ADHD and comorbid psychiatric disorders and their parents reported statistically significantly worse PedsQL scores than healthy children, with large effect sizes across all domains, supporting known-groups discriminant validity. Pediatric patients with ADHD and comorbid psychiatric disorders and their parents reported worse PedsQL scores compared to pediatric patients with cancer and diabetes with the exception of physical health, in which pediatric cancer patients manifested lower physical health, indicating the relative severe impact of ADHD and comorbid psychiatric disorders. More severe ADHD symptoms were generally associated with more impaired PedsQL scores, supporting construct validity. Conclusions: These data demonstrate the feasibility, reliability, and validity of patient self-reported PedsQL 4.0 Generic Core Scales in this high risk population of pediatric patients and highlight the profound negative impact of ADHD and comorbid psychiatric disorders on generic health-related quality of life, comparable to or worse than serious pediatric chronic physical diseases.