Economic evaluation of biological treatments in patients with severe asthma: a systematic review

ABSTRACT

Background

Asthma is a highly prevalent disease, one of the chronic diseases with the highest economic costs; thus, it imposes a high economic burden on society, the healthcare system, patients, and third-party payers. Contrary to this study, until now, systematic reviews of economic evaluations (EEs) of treatments for severe asthma have not been exclusively focused on biological treatments, and have included a small number of studies and only model-based EEs.

Methods

This study systematically reviews EEs of biological therapies for severe asthma published until December 2022 using PRISMA guidelines. The review analyzes the cost-effectiveness of biologicals in comparison to SOC, or SOC plus OCS. The quality of the EEs is assessed using Consensus on Health Economics Checklist extended (CHEC-extended).

Results

Thirty-nine studies were eligible: 15 based on a Markov model, and 19 trial-based; eight adopting societal and NHS perspectives, and seven the payer’s perspective. The reviewed EEs addressed cost-effectiveness, cost-utility, and incremental costs and outcomes comparison. Their findings were mainly expressed through ICER-incremental cost-effectiveness ratio (24 studies: 13 concluded that biological were cost-effective) and cost comparison analysis (14 studies: 6 concluded that biological were cost-effective), and were sensitive to a wide variety of factors (e.g. medication cost, treatment response, time horizon, utility benefits, mortality, exacerbation rate, discount rate, etc.)

Conclusions

There has been some ambiguity concerning the EE of biological therapies due to variation in choice of study design and contradictory results. Nevertheless, it can be concluded that biological treatments improve health outcomes, in many contexts at a high cost.

KEYWORDS:

• Asthma
• Biological therapies
• Cost-effectiveness
• Economic evaluation
• Quality of life

Article highlights

• We systematically review the literature, including both trial-based and model-based EEs of biological therapies for patients with severe asthma, describe the characteristics of the studies, assess their methodological quality, and identify the main drivers of cost effectiveness.

• The significant heterogeneity of the studies makes it difficult to identify patterns that may explain the cost-effectiveness of biological treatments.

• Regardless of the number of studies on omalizumab being much higher than those on any other biologic treatment, results are contradictory for all: around half of the EEs concluded for cost-effectiveness (against another half concluding for non-cost-effectiveness).

• The limited availability of cost-effectiveness thresholds has affected the conclusions of each EE.

• Despite their differences in terms of study design (input parameters and model structures), EEs’ results were consistent enough to give a reliable basis for discussion of overall findings (biological treatments improve health outcomes, in many contexts at a high cost, and with high price sensitivity).

• More EEs are needed: for specific biological therapies and population groups (children), considering the societal perspective, and with more standard study designs that use summary measures that favor comparability, like incremental cost-effectiveness ratio-ICER and QALY.

Declaration of interest

S Alves is a master student at Universidade do Minho; J Rufo is an assistant professor at Instituto de Saúde Pública, Porto, Portugal; J Crispim is an assistant professor at Escola de Economia e Gestão da Universidade do Minho, Braga, Portugal. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

S Alves and J Crispim were involved in study design, data collection, interpretation and discussion of results, appropriate presentation of results, and revising the manuscript. JC Rufo provided clinical input, was involved in study design, interpretation and discussion of results, presentation of results, and revising the manuscript. All authors read the final version of the manuscript critically and approved the final version to be published.

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/14737167.2023.2221435.

Notes

1. https://eppi.ioe.ac.uk/costconversion/

Additional information

Funding

J Rufo is funded by Fundação para a Ciência e Tecnologia through the Stimulus of Scientific Employment, Individual Support (CEECIND) - 3rd Edition (2020.01350.CEECIND). J Crispim is funded by National Funds of the FCT – Portuguese Foundation for Science and Technology within the project No. UIDB/03182/2020.