Note from the National Guideline Clearinghouse (NGC): The National Institute for Health and Clinical Excellence (NICE) commissioned an independent academic centre to perform a systematic literature review on the technology considered in this appraisal and prepare an assessment report. The assessment report for this technology appraisal was prepared by the Centre for Reviews and Dissemination/ Centre for Health Economics (CRD/CHE) Technology Assessment Group, University of York (see the "Availability of Companion Documents" field.)
Search Strategy
Searches were undertaken on the following databases to identify relevant clinical and cost-effectiveness research. Full details of the search strategies are reported in Appendix 10.1 of the Assessment Report (see "Availability of Companion Documents" field):
All databases were searched from their inception to the date of the search. No language or other restrictions were applied.
Searches were also undertaken on several Internet resources, which are documented in Appendix 10.1 of the Assessment Report (see "Availability of Companion Documents" field).
Searches took place over a period of time from April to July 2004.
Terminology
The terms for the search strategies were identified through discussion between an Information Officer and the research team, by scanning the background literature, and by browsing the Medline Medical Subject Headings (MeSH).
Management of References
As several databases were searched, some degree of duplication resulted. To manage this issue, the titles and abstracts of bibliographic records were downloaded and imported into Endnote bibliographic management software to remove duplicate records.
Handsearching
The bibliographies of all included studies and industry submissions made to NICE were reviewed to identify further relevant studies. Handsearching continued throughout the project.
Additional Searches
Additional searches (including citation searches on key papers) were completed as required. See Appendix 1 of the Assessment Report (see "Availability of Companion Documents" field) for full details.
Inclusion and Exclusion of Studies
Study Selection
Two reviewers selected the studies for the review. Discrepancies were resolved by consensus and a third reviewer was consulted when necessary. Each reviewer's decision and a final decision were recorded in the Endnote library.
All titles and abstracts identified by the search were screened and any references that were considered relevant by either reviewer were obtained.
No language restrictions were applied to study selection. Trials reported as full publications or unpublished full reports were included as abstracts only were to be included if adequate information was provided. All of the data submitted by Wyeth and Schering-Plough were considered in the review.
Inclusion/Exclusion Criteria
Studies were included in the review according to the inclusion criteria described in the following paragraphs.
Efficacy of Interventions
The review addressed the following questions about the efficacy of etanercept and infliximab in the treatment of psoriatic arthritis:
- Is treatment effective at all?
- How effective is the treatment?
- Is the drug effective long-term?
- Is there evidence of effect on disease progression?
- Is there is evidence that treatment has a beneficial effect on the psoriasis component of the disease?
- Is there is evidence that treatment improves the functional status of patients?
Intervention
Etanercept administered by subcutaneous injection (SC) and infliximab administered by intravenous infusion were the interventions of interest. Comparisons with either placebo or any other active agent were eligible for inclusion. Trials that compared different regimens of the same disease modifying antirheumatic drug (DMARD) or compared a DMARD with or without a concomitant agent were not included in the review; all such trials identified are listed under excluded studies in Appendix 10.3 of the Assessment Report (see "Availability of Companion Documents" field).
Participants
Studies of adults with psoriatic arthritis were included.
Study Design
Randomised controlled trials were included in the evaluation of efficacy.
Outcomes
The outcomes of primary interest were those of disease activity (those derived from the American College of Rheumatology (ACR) joint count; the Psoriatic Arthritis Response Criteria (PsARC), and the Psoriasis Area and Severity Index (PASI) based measures), those of function and quality of life (Health Assessment Questionnaire (HAQ)) and those of radiological assessment of disease progression. Other outcomes measures of disease activity, function and quality of life and disease progression were considered as necessary given the available trials.
For details of the inclusion/exclusion criteria for studies of adverse events of interventions and disease modifying anti-rheumatoid drugs for treatment of psoriatic arthritis, see sections 3.2.2.2 and 3.2.2.3 in the Assessment Report (see "Availability of Companion Documents" field).
Economic Evaluations – Systematic Review
Studies were eligible for inclusion if they assessed both the costs and benefits (i.e., a full economic evaluation) of either etanercept or infliximab, and compared findings with an appropriate comparator treatment.