A 10-Year Review of the Burden of Uncontrolled Moderate to Severe Asthma

Various unmet needs affect patients with uncontrolled asthma — regardless of access to  inhaled corticosteroid/long-acting β2-agonist (ICS/LABA) therapy — according to the authors of a review published in Respiratory Medicine. The investigators recommended that new treatments be developed to decrease the burden to patients, healthcare systems, and society.

The authors scoured literature published between 2009 and 2019 from the US, United Kingdom, Germany, France, Italy, Spain, Canada, Japan, and Australia to assess the prevalence, clinical measures, health-related quality of life (HRQoL), and economic burden associated with uncontrolled asthma, regardless of patients’ use of ICS/LABA therapy.

Among the 131 records meeting criteria for inclusion in their literature review, the investigators found that the prevalence of uncontrolled asthma varied widely across studies and geographic locations (from a low of 12.9% [26/201] to a high of 100.0% [24/24] in 1 study obese outpatients with severe asthma). Patients had mean/median prebronchodilator FEV₁ measures of 1.69 to 2.45 liters and mean/median pre-bronchodilator percent predicted FEV₁ measures of 57.2 to 79.7 liters, thus indicating poor lung function.

Although values ranged, the annualized rates of exacerbations and severe exacerbations were high (1.30 to 7.30 and 1.66 to 3.60, respectively), and HRQoL burden, which was assessed by means of disease-specific and generic instruments, demonstrated marked impairment.

Direct, indirect, and total costs of resources used to manage uncontrolled asthma were high (approximately £1 billion and $82 billion in the United Kingdom and US, respectively); healthcare consumption by those with uncontrolled asthma was also substantial.

The investigators found that the prevalence of moderate/severe uncontrolled asthma varied greatly by differences in the size and nature of populations studied and how asthma control and severity were defined. In the general asthma population, they found only 1 estimate of uncontrolled asthma in those with severe symptoms (0.2%). This estimate, however, was based on administrative claims data, which do not reflect patient measures of control.

The current study had certain limitations. First, patient samples in some studies were small, and the range of data were very wide for some outcomes, thus impairing generalizability of the results. Second, the authors could only identify a limited number of relevant studies for some findings, which could not necessarily be applied to those with asthma. Third, the focus of the study was the US, Germany, France, Spain, Italy, United Kingdom, Canada, Australia, and Japan, with no relevant data from other countries. Fourth, no studies from low- or middle-income countries were included; in other countries, asthma burden also necessitates improvements of diagnosis and treatment.

“This information provides a comprehensive understanding of disease burden, for payers, providers and policy makers that may help to make informed decisions about the future management of asthma where significant unmet medical need remains pertinent, as well as revealing data gaps that may inform future research,” write the authors.

Disclosure: This research was supported by GSK, and some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.  

Reference

Czira A, Turner M, Martin A, et al. A systematic literature review of burden of illness in adults with uncontrolled moderate/severe asthma. Respir Med. Published online on October 27, 2021. doi:10.1016/j.rmed.2021.106670