Loading ...

TOPLINE:

Nirsevimab implementation in Catalonia, Spain, was associated with a 44% reduction in emergency department (ED) visits for bronchiolitis in infants younger than 6 months and a 48% reduction in hospital admissions compared with previous seasons. The multinational study analyzed 1,574,392 ED visits and 255,689 hospital admissions across Spain, the United Kingdom, and Italy.

METHODOLOGY:

• Researchers conducted a multinational retrospective analysis of ED visits and admissions at 68 hospitals in Catalonia (Spain), one hospital in Rome (Italy), and four hospitals in the United Kingdom from May 1, 2018, to April 30, 2024.
• Analysis included data for all diagnoses, respiratory diagnoses excluding bronchiolitis, and bronchiolitis diagnoses for different age groups (< 6 months, 6-11 months, and 12-23 months).
• A generalized linear model in Poisson regression was utilized to obtain risk ratio and 95% CI of bronchiolitis in the 2023-2024 season compared with a mean of previous seasons, excluding 2020-2021 (as a COVID year).

TAKEAWAY:

• In Catalonia, the risk ratio was 0.52 (95% CI, 0.48-0.55) for bronchiolitis-related hospital admissions in infants aged less than 6 months in the 2023-2024 season compared with previous years.
• ED visits for bronchiolitis in Catalonia showed a risk ratio of 0.56 (95% CI, 0.54-0.58) for infants younger than 6 months and 0.93 (95% CI, 0.89-0.97) for infants aged 6-11 months.
• No significant reduction in risk ratio for ED visits or admissions was observed in the 2023-2024 season at other study sites in the United Kingdom and Italy.
• According to the authors, the effect of nirsevimab was less clear in older infants aged 6-11 and 12-23 months.

IN PRACTICE:

“Nirsevimab had a clear impact in reducing attendances and admissions for infants with bronchiolitis aged < 6 months in Catalonia. However, the impact on older infants was less clear, making it unrealistic to imagine a substantial change in the epidemiology of infants accessing EDs or inpatient wards, at least in the near future,” wrote the authors of the study.

SOURCE:

The study was led by Aida Perramon-Malavez, Computational Biology and Complex Systems Group, Department of Physics, Universitat Politécnica de Catalunya in Barcelona, Spain. It was published online in The Lancet Regional Health – Europe.

LIMITATIONS:

As a retrospective analysis, the study faced several limitations. The proportion of visits and admissions coded as bronchiolitis varied widely across countries, potentially due to coding differences or health system factors rather than true epidemiological differences. The researchers could not directly match all diagnoses in International Classification of Diseases, 10th Revision, to Systematized Nomenclature of Medicine Clinical Terms codes. Limited virology testing of ED visits prevented determination of the relative contribution of respiratory syncytial virus toward the disease burden in the studied seasons.

DISCLOSURES:

Damian Roland disclosed receiving grants from Wellcome Trust, Respiratory Syncytial Virus Consortium in Europe, Imperial College London, and National Institute for Health Research. Antoni Soriano-Arandes reported receiving consulting fees and honoraria for lectures from Sanofi, MSD, and Pfizer, along with grants from La Marató de TV3. Additional disclosures are noted in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.