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Cost effectiveness of levocetirizine in chronic idiopathic urticaria: a pooled analysis of two randomised controlled trials |
Kapp A, Demarteau N |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology The authors compared levocetirizine (Xysal; UCB, Braine L'Alleud, Belgium), a highly selective H1-receptor antagonist, with placebo. Levocetirizine was given daily as 5-mg tablets.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients with chronic idiopathic urticaria (CIU). Patients were included if they had episodes of hives of characteristic wheal and flare appearance occurring regularly (at least three times per week for at least 6 weeks in the previous 3 months) without identifiable cause.
Setting The setting was outpatient care. The economic study was carried out in France.
Dates to which data relate The effectiveness data came from studies published in 2004 and 2005. The costs were reported in 2002 prices.
Source of effectiveness data The primary clinical data were the number of pruritus-free days (PFDs), which were obtained through pooling. This was a newly devised parameter as CIU was reported to have not been assessed before using health-economic techniques.
Sources searched to identify primary studies The data were obtained from two randomised, placebo-controlled, double-blind trials. These studies were both carried out over a time horizon of 4 weeks and were based in multiple centres. One study was a dose-ranging study and the other used fixed dosages, otherwise they followed the same design.
Methods used to judge relevance and validity, and for extracting data The authors selected two studies that they had carried out to provide clinical data relevant to their economic study question. They also carried out a review of the literature using MEDLINE, EMBASE and SciSearch. However, it would appear that this was done to establish the level of economic evidence available in the literature, rather than to identify clinical studies that could be used as inputs.
Measure of benefits used in the economic analysis The authors used the number of PFDs as their summary measure of health outcome. This was obtained directly from the review of effectiveness.
Direct costs Direct medical costs incorporated the numbers of medication events, medical procedures and hospitalisations related to CIU or to the adverse effects of the study medication. The costs for medication events were taken from the package cost reported in the VIDAL, while other unit costs were obtained from official websites. The costs were estimated from a French societal perspective and were reported in 2002 prices. Discounting was not required because of the very short time horizon of the study (4 weeks).
Statistical analysis of costs The mean number of medications was compared using a Poisson regression model. A variance stabilised bootstrap-t method was used for the comparison of productivity costs.
Indirect Costs Productivity implications took absenteeism (full days of work) and presenteeism (productivity lost while at work) into account. They were reported as the mean number of days lost per patient per month. The data were collected using the Pharmacoeconomic Indirect Costs (PIC) questionnaire and were valued using the human capital approach.
Sensitivity analysis The authors used inference regarding mean costs, and a Bayesian bootstrap with 2,000 samples to understand the impact of uncertainty. Confidence intervals (CIs) were also generated using the bootstrapping technique.
Estimated benefits used in the economic analysis The number of PFDs at baseline was 1.3 for placebo and 1.9 for levocetirizine (not significantly different).
The number of PFDs after treatment was 5.5 for placebo and 12 for levocetirizine, (p<0.001).
An additional 6.5 PFDs (95% CI: 3.8 to 9.3) were gained in the levocetirizine group.
Cost results The total direct costs were EUR 13.82 (95% CI: 2.61 to 48.86) for placebo and EUR 13.45 (95% CI: 13.29 to 13.70) for levocetirizine. The difference was -EUR 0.37 (95% CI: -37.04 to 10.71).
The total productivity costs were EUR 163.54 (95% CI: 97.44 to 244.74) for placebo and EUR 71.99 (95% CI: 33.63 to 133.58) for levocetirizine. The difference was -EUR 91.55 (95% CI: -185.84 to 3.71).
The total overall costs were EUR 177.36 (95% CI: 109.88 to 263.22) for placebo and EUR 85.43 (95% CI: 47.04 to 147.05) for levocetirizine. The difference was -EUR 91.93 (95% CI: -188.48 to -0.68), (p<0.05).
Synthesis of costs and benefits Levocetirizine showed improved effectiveness compared with placebo and was cost-saving from the societal perspective. It was cost-neutral from the perspective of the health care payer (direct costs only).
A total of 98.4% of the bootstrap replications were within the dominant quadrant, indicating improved effectiveness and cost-savings from the societal perspective. The comparable statistic for the health care payer perspective was 39.9%.
Authors' conclusions Levocetirizine is dominant over placebo for the treatment of chronic idiopathic urticaria (CIU).
CRD COMMENTARY - Selection of comparators The authors compared levocetirizine against placebo, enabling them to demonstrate the active value of the drug. However, their results might not represent the true value of the drug relative to benefits gained from drugs already adopted into clinical practice.
Validity of estimate of measure of effectiveness The authors clearly stated the sources of their effectiveness estimates, thus enabling the reader to verify them and to assess the comparability of the sources within their own setting. However, the validity of the results would have been improved had the authors used the review they carried out to justify inclusion of these two trials only, or to capture data that could have been used to validate the actual data used. It was unclear from the reporting whether the best available evidence had been used to inform the economic evaluation. The use of a systematic review to identify the clinical trials is considered the 'gold' standard.
Validity of estimate of measure of benefit The number of PFDs was used as the summary measure of health benefit. The authors devised this measure since they reported that CIU had not been assessed before using health-economic techniques. Such a measure may be comparable to the results of other economic analyses that explore the number of event-free or symptom-free days. However, the authors acknowledged that this measure does not explore quality of life, which is also likely to be affected by this treatment. Future work could use a quality of life-related outcome measure.
Validity of estimate of costs The authors adopted the perspective of French society and explored both direct and productivity costs as appropriate. Within these categories the authors examined relevant cost elements, provided the source of information, and broke down total cost elements to demonstrate the importance of each element. The fact that many cost results were not significantly different suggests that changes in the inputs, owing to changes in the perspective or omissions, might have a considerable effect on the results and, subsequently, on the principle conclusions drawn.
Other issues As the authors reported, they were unable to compare their results with those from other studies as this was the first time CUI had been the topic of an economic analysis. The issue of the generalisability of the results was considered, and was noted to be limited by the use of French resources/costing. However, the authors argued that, as treatment patterns across European countries are relatively similar, resource use could be expected not to "differ substantially". Nevertheless, the authors appropriately recommended that extrapolation "should only be performed with great caution". The study was very transparent and easy for the reader to understand, the results followed clearly from the study design, and the conclusions were an accurate reflection of the results presented. A number of limitations were identified. For example, the limited time horizon, the use of clinical trials that reduce the direct applicability of the results to real life, and the use of placebo as the comparator.
Implications of the study The authors did not make any recommendations for policy or practice following on from their study. The need for further work in this area is clear.
Bibliographic details Kapp A, Demarteau N. Cost effectiveness of levocetirizine in chronic idiopathic urticaria: a pooled analysis of two randomised controlled trials. Clinical Drug Investigation 2006; 26(1): 1-11 Other publications of related interest Because readers are likely to encounter and assess individual publications, NHS EED abstracts reflect the original publication as it is written, as a stand-alone paper. Where NHS EED abstractors are able to identify positively that a publication is significantly linked to or informed by other publications, these will be referenced in the text of the abstract and their bibliographic details recorded here for information.
Kapp A, Pichler JW. Levocetirizine is an effective treatment in patients suffering from chronic idiopathic urticaria: a randomised double-blind placebo controlled parallel multicentre study. Int J Dermatol 2006;45:469-74.
Kapp A, Wedi B. Chronic urticaria: clinical aspects and focus on a new antihistamine, levocetirizine. J Drugs Dermatol 2004;3:632-9.
Indexing Status Subject indexing assigned by NLM MeSH Adult; Anti-Allergic Agents /therapeutic use; Cetirizine /economics /therapeutic use; Chronic Disease; Cost-Benefit Analysis; Female; Health Care Costs; Humans; Male; Piperazines /economics /therapeutic use; Randomized Controlled Trials as Topic; Urticaria /drug therapy AccessionNumber 22007006041 Date bibliographic record published 30/09/2007 Date abstract record published 30/09/2007 |
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