Impact of attention-deficit/hyperactivity disorder (ADHD) on prescription dug spending for children and adolescents: increasing relevance of health economic evidence

Abstract

Background: During the last decade, pharmaceutical spending for patients with attention-deficit-hyperactivity disorder (ADHD) has been escalating internationally.

Objectives: First, to estimate future trends of ADHD-related drug expenditures from the perspectives of the statutory health insurance (SHI; Gesetzliche Krankenversicherung, GKV) in Germany and the National Health Service (NHS) in England, respectively, for children and adolescents age 6 to 18 years. Second, to evaluate the budgetary impact on individual prescribers (child and adolescent psychiatrists and pediatricians treating patients with ADHD) in Germany.

Methods: A model was developed to predict plausible scenarios of future pharmaceutical expenditures for treatment of ADHD. Model inputs were derived from demographic and epidemiological data, a literature review of past spending trends, and an analysis of new pharmaceutical products in development for ADHD. Only products in clinical development phase III or later were considered. Uncertainty was addressed by way of scenario analysis. For each jurisdiction, five scenarios used different assumptions of future diagnosis prevalence, treatment prevalence, rates of adoption and unit costs of novel drugs, and treatment intensity.

Results: Annual ADHD pharmacotherapy expenditures for children and adolescents will further increase and may exceed euro 310 m (D; E: 78 m) in 2012 (2002: approximately euro 21.8 m; approximately 7.0 m). During this period, overall drug spending by individual physicians may increase 2.3- to 9.5-fold, resulting from the multiplicative effects of four variables: increased number of diagnosed cases, growing acceptance and intensity of pharmacotherapy, and higher unit costs of novel medications.

Discussion: Even for an extreme low case scenario, a more than six-fold increase of pharmaceutical spending for children and adolescents is predicted over the decade from 2002 to 2012, from the perspectives of both the NHS in England and the GKV in Germany. This budgetary impact projection represents a partial analysis only because other expenditures are likely to rise as well, for instance those associated with physician services, including diagnosis and psychosocial treatment. Further to this, by definition budgetary impact analyses have little to nothing to say about clinical appropriateness and about value of money.

Conclusion: Providers of care for children and adolescents with ADHD should anticipate serious challenges related to the cost-effectiveness of interventions.

Figure 1

ADHD-related prescriptions and expenditures in England, 1998 – 2005. a: Prescription items dispensed in the community; b: Expenditures by category p.a.; DEX: dexamphetamine (Dexedrine^R and others); MPH: methylphenidate; IR: immediate-release formulations (Ritalin^R and generics); MR: modified-release formulations (Concerta^R XL, Equasym^R XL; Ritalin^R SR imports); MOD: modafinil (Provigil^R, licensed for daytime sleepiness); ATX: atomoxetine (Strattera^R); PEM: pemoline (Volital^R, before 2002 only, not shown due to small volume); data source: NHS Prescription Cost Analysis 1999–2006 [19]. Note that these data include prescriptions for adults with ADHD and also for other indications (narcolepsy).

Figure 2

Methylphenidate prescriptions trend in Germany, 1992 – 2005. Methylphenidate prescriptions grew 47-fold from 1992 to 2005. During the same period, total prescriptions in Germany declined by 41 percent. Data source: Wissenschaftliches Institut der AOK, Schwabe and Paffrath, 1993 – 2006 [20]; note change of database for year 2001/2002. All data refer to prescriptions reimbursed by statutory health insurance (SHI, "GKV", covering approximately 90 percent of German population); excluding parallel imports. Note that these data include prescriptions for adults with ADHD and also for other indications (narcolepsy).

Figure 3

Projected prescription drug expenditures for ADHD in children and adolescents, 2001 – 2012 (base case). a, b: Defined daily doses (DDDs) p.a.; c, d: expenditures by category p.a.; e, f: total (cumulated) expenditures p.a.; left: England; right: Germany. MPH: methylphenidate; IR: immediate-release formulations (Ritalin^R, branded generics [Equasym^R, Medikinet^R], generics; Focalin^R); MR: modified-release formulations (Concerta^R XL, Equasym^R XL, Medikinet^R retard, Focalin^R XR; MPH-Patch: transdermal system (Daytrana^R); LisDEX: lisdexamphetamine (NRP104); Nonstimulants: atomoxetine (Strattera^R), armodafinil (Nuvigil^R); DEX: dexamphetamine (England only).

Figure 4

Range of plausible projections: expenditures under extreme case scenarios, 2001–2012. a, b: "High Extreme" Case; c, d: Base Case modified "LisDEX without clinical advantage over MPH-MR"; e, f: "Low Extreme" Case; left: England; right: Germany. MPH: methylphenidate; IR: immediate-release formulations (Ritalin^R, branded generics [Equasym^R, Medikinet^R], generics; Focalin^R); MR: modified-release formulations (Concerta^R XL, Equasym^R XL, Medikinet^R retard, Focalin^R XR; MPH-Patch: transdermal system (Daytrana^R); LisDEX: lisdexamphetamine (NRP104); Nonstimulants: ATX, atomoxetine (Strattera^R), ARM, armodafinil (Sparlon^R); DEX: dexamphetamine (England only).

Figure 5

Projected impact of ADHD treatment for children and adolescents on individual physicians' prescription drug expenditures, 2001–2012 (base case). a: Child and adolescent psychiatrists; b: pediatricians in private practice in Germany. Expenditures expressed as €/physician and year; perspective of statutory health insurance (i.e., excluding privately health insured patients). Data represent average values for one of the upper 50% of child and adolescent psychiatrists and one of the upper 20% of pediatricians in terms of relative involvement in care for ADHD patients, respectively. Concentration of care modeled according to Nordbaden data [74]. Abbreviation: Non-ADHD-Rx: expenditures for treatment of conditions other than ADHD.