Trends in hospitalisations for lower respiratory infections after the COVID-19 pandemic in France

Objectives

We aimed to evaluate the impact of the pandemic and post-pandemic periods on hospital admissions for LRTI, with a focus on patients with chronic respiratory disease (CRD).

Methods

From July 2013 to June 2023, monthly numbers of adult hospitalisations for LRTI (excluding SARS-CoV-2) were extracted from the French National Hospital Discharge Database. They were modelled by regressions with autocorrelated errors. Three periods were defined: (1) early pandemic and successive lockdowns; (2) gradual lifting of restrictions and widespread SARS-CoV-2 vaccination; (3) withdrawal of restriction measures.

Results

Pre-pandemic incidence was 96 (90.5 to 101.5) per 100,000 population. Compared with the pre-pandemic period, no more seasonality and significant reductions were estimated in the first two periods: −43.64% (−50.11 to −37.17) and −32.97% (−39.88 to −26.05), respectively. A rebound with a positive trend and a seasonal pattern was observed in period 3. Similar results were observed for CRD patients with no significant difference with pre-pandemic levels in the last period (−9.21%; −20.9% to 1.67%), albeit with differential changes according to the type of CRD.

Conclusions

COVID-19 pandemic containment measures contributed to changes in LRTI incidence, with a rapid increase and return to a seasonal pattern after their lifting, particularly in patients with CRD.