Dissertation Title: "The Health-Related Quality of Life of Children Ages 7-10 with Attention Deficit Hyperactivity Disorder (ADHD) and the Cost-Effectiveness of Treating ADHD in These Children"Attention Deficit Hyperactivity Disorder (ADHD) causes chronic impairments in attention and hyperactivity in an estimated 3-7% of U.S. children, but its impact on their health-related quality of life, and the cost-effectiveness of treatments for ADHD, have not been well characterized. Chapter 1 describes an Internet-based survey using a convenience sample of 113 parents with children ages 7-10 years with combined-type ADHD. The survey measured ADHD severity by the Swanson, Nolan, and Pelham (SNAP-IV) index, and included the parent proxy version of the Health Utilities Index (Mark 3) (HUI-3) to assess the impact of combined type ADHD on the health-related quality of life. We assessed the context validity of the HUI-3 in ADHD, and used a linear regression model to predict the HUI-3 score. The results of this analysis show that ADHD causes significant impairment in the health-related quality of life of children ages 7-10 years.
In Chapter 2, we used the linear regression equation to predict the HUI-3 scores for a sample of children treated in a large randomized clinical trial, the Multimodal Treatment of ADHD (MTA). Using the data from the predictive model and the MTA results, we estimated the incremental costs (in 2006 U.S. dollars) and effectiveness (in quality-adjusted life years, QALYs) of four treatment modalities: standard methods for community care, behavioral treatment, managed medication, and the combination of managed medication and behavioral treatments. The results show that carefully managed medication appears highly cost-effective compared to community care (incremental cost-effectiveness ratio of $3,300/QALY). Behavioral treatment and combination treatment are dominated in comparison to managed medication, even for the patients with multiple comorbid illnesses in addition to ADHD. Carefully controlled management of medication remained cost-effective at the cost of newer medications currently on the market.
Finally, Chapter 3 compares the utility scores derived from the HUI-2 and HUI-3 in children with ADHD. Consistent with prior research, we found lower derived utilities from the HUI-3 than from the HUI-2. Scale differences account for 60% of the difference between the two versions of the HUI. Our results suggest that the HUI-3 provides more sensitivity to the health-related quality of life decrements associated with more severe levels of ADHD symptoms.