Respective roles of non-pharmaceutical interventions in bronchiolitis outbreaks: an interrupted time-series analysis based on a multinational surveillance system

Lea Lenglart*, Naim Ouldali, EPISODES Study Group, Kate Honeyford, Zsolt Bognar, Silvia Bressan, Danilo Buonsenso, Liviana Da Dalt, Tisham De, Ruth Farrugia, Ian K. Maconochie, Henriette A. Moll, Rianne Oostenbrink, Niccolo Parri, Damian Roland, Katy Rose, Esra Akyüz Özkan, François Angoulvant, Camille Aupiais, Clarissa BarberMichael Barrett, Romain Basmaci, Susana Castanhinha, Antonio Chiaretti, Sheena Durnin, Patrick Fitzpatrick, Laszlo Fodor, Borja Gomez, Susanne Greber-Platzer, Romain Guedj, Florian Hey, Lina Jankauskaite, Daniela Kohlfuerst, Ines Mascarenhas, Anna Maria Musolino, Zanda Pučuka, Sofia Reis, Alexis Rybak, Petra Salamon, Matthias Schaffert, Keren Shahar-Nissan, Maria Chiara Supino, Ozlem Teksam, Caner Turan, Roberto Velasco, Ruud G. Nijman, Luigi Titomanlio, Marcello Covino, Alberto Villani, Katharina Lieb, Florian Hoffmann

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

9 Citations (Scopus)


Background Bronchiolitis is a major source of morbimortality among young children worldwide. Non-pharmaceutical interventions (NPIs) implemented to reduce the spread of severe acute respiratory syndrome coronavirus 2 may have had an important impact on bronchiolitis outbreaks, as well as major societal consequences. Discriminating between their respective impacts would help define optimal public health strategies against bronchiolitis. We aimed to assess the respective impact of each NPI on bronchiolitis outbreaks in 14 European countries. Methods We conducted a quasi-experimental interrupted time-series analysis based on a multicentre international study. All children diagnosed with bronchiolitis presenting to the paediatric emergency department of one of 27 centres from January 2018 to March 2021 were included. We assessed the association between each NPI and change in the bronchiolitis trend over time by seasonally adjusted multivariable quasi-Poisson regression modelling. Results In total, 42 916 children were included. We observed an overall cumulative 78% (95% CI −100–−54%; p<0.0001) reduction in bronchiolitis cases following NPI implementation. The decrease varied between countries from −97% (95% CI −100– −47%; p=0.0005) to −36% (95% CI −79–7%; p=0.105). Full lockdown (incidence rate ratio (IRR) 0.21 (95% CI 0.14–0.30); p<0.001), secondary school closure (IRR 0.33 (95% CI 0.20–0.52); p<0.0001), wearing a mask indoors (IRR 0.49 (95% CI 0.25–0.94); p=0.034) and teleworking (IRR 0.55 (95% CI 0.31–0.97); p=0.038) were independently associated with reducing bronchiolitis. Conclusions Several NPIs were associated with a reduction of bronchiolitis outbreaks, including full lockdown, school closure, teleworking and facial masking. Some of these public health interventions may be considered to further reduce the global burden of bronchiolitis.

Original languageEnglish
Article number2201172
JournalEuropean Respiratory Journal
Issue number2
Early online date16 Feb 2023
Publication statusPublished - 2023

Bibliographical note

Support statement: N. Ouldali is supported by the ESPID 2021-2023 fellowship award, R.G. Nijman by the NIHR ACL 2018-021-007 award and K. Honeyford by the NIHR (HS&DR) project NIHR129082. Funding information for this article has been deposited with the Crossref Funder Registry.

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Copyright © The authors 2023.


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