A systematic review of the effectiveness of adalimumab

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Health economics
TABLE 19 Summary of published economic analyses
Study TNF inhibitor(s) Form of economic Model used Time-horizon
considered analysis
Choi et al., 2002159 Etanercept Cost-effectiveness Decision tree 6 months
Brennan et al., 2004160 Etanercept Cost–utility Patient-level simulation Lifetime
Wong et al., 2002161 Infliximab Cost–utility Markov Lifetime
Kobelt et al., 2003162 Infliximab Cost–utility Markov 10 years
Jobanputra et al., 20021 Etanercept, infliximab Cost–utility Patient-level simulation Lifetime
Kobelt et al., 2004163 Etanercept, infliximab Cost–utility NA NA
Chiou et al., 2004164 Etanercept, infliximab,
adalimumab
Cost–utility Decision tree 1 year
Welsing et al., 2004 165 Etanercept Cost–utility Markov 5 years
Bansback et al., 2005166 Etanercept, infliximab,
adalimumab
Cost–utility Patient-level simulation Lifetime
Kobelt et al., 2005 167 Etanercept Cost–utility Markov 10 years
Study selection, data extraction, and quality
assessment strategy
An experienced health economist applied the
inclusion and exclusion criteria. Data were
extracted by one reviewer using a predesigned
data extraction form and were independently
checked by a second reviewer. Data on the
following were sought:
● study characteristics, such as form of economic
analysis, population, interventions,
comparators, perspective, time-horizon and
modelling used
● effectiveness and cost parameters, such as
effectiveness data, health state valuations
(utilities), resource-use data, unit cost data,
price year, discounting and key assumptions
● results and sensitivity analyses.
These characteristics and the main results of
included economic evaluations are summarised in
subsequent tables. The quality of included studies
and industry submissions was assessed using the
CHEC list. 158 The study question, selection of
alternatives, form of evaluation, effectiveness data,
costs, benefit measurement and valuation, decision
modelling, discounting, allowance for uncertainty
and presentation of results were all evaluated as
part of this process.
Results of systematic review of
economic evaluations
Ten published studies, including one by the
current authors, 1 met the inclusion criteria. Given
that Jobanputra 1 describes the initial version of
BRAM which is updated in this report, it will not
be further discussed here. Key features of the nine
other studies are summarised in Table 19. In
addition, all three manufacturers submitted
economic analyses and models. These submissions
are reviewed in detail in the section ‘Review of
industry cost-effectiveness submissions’ (p. 80).
Details of the nine studies are presented in
Appendix 8, using a simplified version of the
Drummond and Jefferson checklist. A summary of
the ICERs for TNF inhibitors reported in
published papers is provided in Table 20.
Four economic evaluations only considered
etanercept compared with specified DMARDs or
sequences of DMARDs (Table 21). Three studies
were cost–utility analyses, with the cost-effectiveness
ratio (ICER) reported as cost per QALY gained
(Table 21). In addition to cost per QALY, Welsing
and colleagues 165 considered cost per patient-year
in three DAS28 states. Choi and colleagues 159 used
the ACR20 response and a weighted average of
proportions of patients achieving ACR70, ACR50
and ACR20 (ACR weighted response, ACR70WR)
and reported the cost-effectiveness ratio as cost
per ACR20 or ACR70WR. Brennan and
colleagues 160 carried out the analysis from a
healthcare perspective, whereas the other studies
included direct and indirect costs. The four studies
differed in how etanercept use was modelled: Choi
and colleagues 159 considered etanercept alone
over a short period of 6 months; Brennan and
colleagues 160 placed etanercept as third line
therapy in a DMARD sequence over a patient
lifetime; Welsing and colleagues 165 considered
three different etanercept pathways (etanercept
first, then switch to conventional DMARDs if there