A systematic review and economic model of the effectiveness and ...

Aim
The aim of this chapter is to review the published
literature and company submissions to the NICE
on the QoL and cost-effectiveness of
● oral MPH including Ritalin [Immediate Release
(IR-MPH), Equasym (IR-MPH), Equasym ® XL
(Extended Release ER-MPH8 hour) and
Concerta® XL (ER-MPH12 hour)]
● DES (Dexedrine)
● ATX (Strattera)
in children and adolescents (under 18 years of
age) diagnosed with ADHD (including HKD). All
studies in which MPH, DEX or ATX were used
alone or in combination with other drugs or nondrug
interventions [e.g. psychological/behavioural
therapy (BT)] are included.
Literature review
The information scientist conducted a search on
the published QoL and cost-effectiveness literature
(see Appendix 2 for full details of the search
strategies and databases used). The QoL searches
identified 500 records (853 records before deduplication,
that is, before eliminating duplicates)
that were assessed by the health economist for
relevance. In addition, the 38 records (47 before
de-duplication) identified from the databasespecific
searches for economic evaluations and the
6535 records (2450 before de-duplication)
identified by the generic and adverse event
searches were also sifted for relevant papers in
relation to the cost-effectiveness of named drug
therapies for ADHD. Five relevant costeffectiveness
and two relevant HRQoL papers
were identified from the searches.
QoL studies were ordered if they contained health
outcome data for use in economic evaluations of
ADHD. The review of the economic evaluation
literature included studies that compared two or
more ADHD interventions in terms of their costs
and outcomes and where at least one drug
intervention was assessed. Economic evaluations
Chapter 5
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Health Technology Assessment 2006; Vol. 10: No. 23
Review of economic evaluations of ADHD drug
interventions in children and adolescents
included cost–consequence, cost–utility, costeffectiveness,
cost-minimisation and cost–benefit
analyses. Economic evaluations reported as
conference proceedings or abstracts were excluded
since the data they contain may not be complete.
Thirty-one QoL studies and five economic
evaluation studies were ordered, of which two QoL
studies and five economic evaluations were
reviewed. A data extraction form used in previous
Technology Assessment Reviews was used to
abstract data on all economic evaluations reviewed
(Appendix 7). Each economic evaluation was
quality assessed independently by two health
economists (Appendix 6) based on an economic
evaluation checklist. 115
Review of quality of life and
cost-effectiveness literature
Quality of life
Searches (see Appendix 2) for studies on the QoL
of children and adolescents with ADHD revealed a
plethora of instruments, the majority measuring
multiple, disaggregated dimensions of health
designed to identify the extent to which health
status is affected by the intervention in question.
As such, many featured as outcome measures in
the trials that are reviewed in the clinical
effectiveness chapter (Chapter 4).
Two main types of instruments were used to
evaluate ADHD interventions including those
measuring (1) symptoms and functionality [e.g.
the Peabody Individual Achievement Test
(PIAT)] 116 and those measuring (2) (HRQoL) in
children with ADHD. The HRQoL instruments
used included disease-specific instruments such as
the (SNAP-IV) Rating Scale, 117 CTRS and
CPRS. 118 A few instruments were generic measures
that can be used to compare effectiveness across
diseases, for example, the Index of Health Related
Quality of Life (IHRQoL) 119 or the generic
paediatric measures, for example the Child Health
Questionnaire (CHQ). 120
The choice of outcome measure is a critical design
issue. ADHD is a complex neuro-developmental
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