Treatment for ADHD: is more complex treatment cost-effective for more complex cases?

Health Services Research, Feb, 2007 by E. Michael Foster, Peter S. Jensen, Michael Schlander, William E. Pelham, Jr., Lily Hechtman, L. Eugene Arnold, James M. Swanson, Timothy Wigal

Attention problems are among the most common of mental/emotional/behavioral disorders among children and youth (U.S. Department of Health and Human Services 1999). Youth with attention deficit hyperactivity disorder (ADHD) are more likely to be involved in a variety of costly behaviors including substance use and abuse (Daley 2004) and delinquency (Richardson 2002) as well as to receive costly services. These children also are likely to receive additional school services, including (but not limited to) special education (Jones, Foster, and Gottschall 2005).Jones et al. (2005) estimate that the costs of such services can exceed $10,000 per year. These costs represent only some of the costs that appear on public budgets. These behaviors generate even larger costs to society, such as the costs to victims of violence or the broader costs of school failure (Haveman and Wolfe 1984). These figures suggest that a policy maker's willingness to pay for effective treatments should be quite high. As discussed below, this willingness to pay is a key determinant of a program's cost-effectiveness.

Fortunately, effective treatments exist, notably behavioral treatment and psycho-stimulants. A key issue in the field involves the degree to which each of these treatments is more (or less) effective and cost-effective when combined with the other (Jensen 2000).

Assessment of treatment effectiveness is complicated by comorbidities, including conduct disorder and anxiety. These conditions amplify the link between ADHD and service use (Vostanis et al. 2003) and raise the risk for poor long-term outcomes, such as violence and substance abuse (Arseneault et al. 2000).

In contrast to efficacy and effectiveness, little is known about the cost-effectiveness of alternative treatments, either separately or in combination. To address this issue, we use data from one of the largest and most influential studies in the field, the Multimodal Treatment Study of Children with ADHD (MTA) (The MTA Cooperative Group 1999). The MTA was designed to compare the effectiveness of psychosocial (behavioral) treatment versus medication, and determine whether the two modalities are more effective when delivered together.

An earlier cost-effectiveness analysis of MTA data focused on core attention and related symptoms in the whole sample (Jensen et al. 2005). The analyses presented here extend that earlier work in three ways. First, we examine a broader measure of functional impairment, the Columbia Impairment Scale (CIS). Second, we examine how cost-effectiveness varies with comorbidities. Third, we use new methodology for examining cost-effectiveness of treatments, the cost-effectiveness acceptability curve (CEAC) (Hoch, Briggs, and Willan 2002).

PRIOR RESEARCH

Two areas of prior work inform this research: that on the cost-effectiveness of treatment for ADHD and earlier research on MTA.

Prior Research on Cost-Effectiveness of Treatment for ADHD

In addition to the Jensen et al. analyses (discussed below), economic evaluations of ADHD treatment have been published for Canada and the United Kingdom (UK). Miller et al. (1998) compared six treatments: methylphenidate, dextroamphetamine, pemoline (high-dose and low-dose), nondrug therapy, combined therapy, and no treatment. The study considers costs and outcomes over a 1-year period; the study's perspective is that of third-party payers. On the basis of prior research, treatment effects were determined using a measure of symptoms, the Conners Teacher Rating Scale (CTRS). The methylphenidate strategy was more effective and cheaper than other medication therapies and behavioral therapy as well as combination therapy. Relative to no treatment, methylphenidate was associated with incremental costs of 498 CAN-$ per 6-point (or 1 SD) improvement of the CTRS score.

In the United Kingdom, Gilmore and Milne (2001) examined the cost-effectiveness of different medications from the perspective of the UK National Health Service (NHS). Methylphenidate was cost-effective in children with hyperkinetic disorder according to ICD-10 criteria. This study considered neither behavioral nor combined treatment strategies, however (Gilmore and Milne 2001). The UK National Institute of Clinical Excellence (NICE) estimated the cost per quality-adjusted life year (QALY) gained by methylphenidate at 9,200 [pounds sterling] to 14,600 [pounds sterling] (Lord and Paisley 2000). In a further study from the perspective of the UK NHS, a once-daily modified-release preparation of methylphenidate showed extended dominance over immediate-release methylphenidate (both combined with behavioral treatment) over a wide range of assumptions (Schlander 2004). To date, all UK analyses have used a 1-year time horizon.

Prior Research on MTA

The MTA study has been the subject of substantial research and some debate. Five hundred and seventy-nine children ages 7-9.9 were randomized to one of four treatment arms: assessment and referral to community care (CC); intensive, systematic medication management (MedMgt); multicomponent behavioral treatment (Beh); and a combination of behavioral treatment and medications (Comb). The MTA-administered interventions were high quality. In the case of MedMgt, dosage was carefully titrated, and participants met with their physician monthly, who consulted the child's teacher regarding classroom performance. Beh was multicomponent and targeted multiple aspects of the child's life. (For details, see Wells et al. 2000.) These components included parent training, a two-part school intervention component, and a child treatment component anchored in an intensive summer treatment program. Each treatment continued for 14 months, although Beh was faded to monthly parent group sessions over the last 3-5 months.