Cost effectiveness of pharmacotherapies for attention-deficit hyperactivity disorder: a systematic literature review

Attention-deficit hyperactivity disorder (ADHD) is a common psychiatric disorder that impairs the quality of life for patients and their families and is associated with considerable direct and indirect costs. Pharmacotherapies for ADHD, including stimulants and non-stimulants, are often used to treat patients with ADHD. However, the costs, effectiveness and adverse effects of these agents vary. Therefore, information regarding the cost effectiveness of different pharmacological treatments is needed to better inform payers in the allocation of limited resources.

The objectives of this study were to conduct a systematic literature review of economic evaluations of pharmacotherapies for ADHD treatments and to assess the cost effectiveness of different interventions based on the existing studies.

A systematic literature review of economic evaluations of pharmacotherapies for ADHD was conducted in MEDLINE, the National Health Services (NHS) Economic Evaluation database and EMBASE. For inclusion in this review, studies had to compare two or more ADHD interventions with at least one pharmacotherapy, assess both costs and outcomes, and be conducted between 1990 and 2011 in North America, Europe, Australia or New Zealand. Studies were excluded if they were not original research, were presented only as conference proceedings or abstracts or did not report costs associated with specific interventions. The study quality was assessed using the British Medical Journal (BMJ) health economics checklist. The literature search, data extraction and quality assessment were performed by one author and independently checked for accuracy by a second author. Discrepancies were resolved by consensus and referring to the original article. If necessary, a third reviewer was consulted.

The initial search returned 93 citations from MEDLINE, 10 from the NHS Economic Evaluation database and 377 from EMBASE. Thirteen papers met the inclusion/exclusion criteria and were included in the review. Based on the BMJ checklist, all these studies were considered to be of sufficient quality to be included in the literature review, but they varied substantially in target population, methodology and effectiveness measures. Identified pharmacotherapies were cost effective compared with no treatment, placebo, behavioural therapy or community care among children and adolescents with ADHD. Studies comparing non-stimulants with stimulants and amfetamine with methylphenidate stimulants showed inconsistent findings. A limited number of studies indicated that methylphenidate Osmotic-controlled Release Oral delivery System (OROS) was cost effective compared with short-acting methylphenidate. There were no published studies on the cost effectiveness of pharmacotherapy in the adult ADHD population, comparing stimulants, non-stimulants or adjuvant therapy. There is limited evidence on the long-term cost effectiveness of pharmacotherapies.

Among children and adolescents with ADHD, there was consistent evidence that pharmacotherapies are cost effective compared with no treatment or behavioural therapy. Adequate data are lacking to draw conclusions regarding the relative cost effectiveness of different pharmacological agents. More economic evaluations with standardized methods, such as effectiveness measures and cost components, are warranted. To better inform payers about the economic value of existing medications, future studies should also consider identifying subgroups that may have heterogeneous responses to different treatments, including analyses of recently approved treatments (e.g. lisdexamfetamine, guanfacine extended-release and clonidine extended-release) and expanding the time horizon to incorporate long-term outcomes.