Impact of non-pharmaceutical interventions during the early phase of COVID-19 pandemic on paediatric ICU admissions in Canada and France: a multicentre descriptive cohort and interrupted time-series analysis of non-SARS-CoV-2 viral admissions

Introduction: The COVID-19 pandemic led many countries to implement non-pharmaceutical interventions (NPIs), substantially altering paediatric healthcare. This study evaluated the impact of NPIs on morbidity and non-SARS-CoV-2 infections in paediatric intensive care units (PICUs) during the first wave of the COVID-19 pandemic. Methods: A descriptive, retrospective cohort study was conducted across three geographically distinct PICUs in Canada and France, covering January 2016 to July 2020. To assess the impact of NPIs, disease categories, patient morbidity, the length of PICU stay, mortality and the spectrum of non-SARS-CoV-2 viruses detected from April to July in 2016-2019 were compared with the same period in 2020. Additionally, a time-series analysis of non-SARS-CoV-2 virus-related PICU admissions was performed. Results: Among 12 873 patients, median age was 28.8 months (IQR 5.4-111.0), 32.3% required invasive mechanical ventilation, median PICU stay was 3.0 days (IQR 1.6-5.0) and mortality was 3.2%. Comparing the prepandemic and pandemic eras during April-July, the proportion of respiratory admissions declined significantly (29.4% vs 19.4%, p<0.01), while that of postoperative admissions remained stable (25.2% vs 22.9%, p=0.23). No significant differences were seen in ventilation use, length of stay or mortality. Time-series analysis showed a decreasing trend in non-SARS-CoV-2 viral admissions after the index date: OR 0.57 (95% CI 0.31 to 1.02) in weeks 0 to <2, 0.14 (0.08 to 0.25) in weeks 2 to <4 and 0.04 (0.02 to 0.06) in weeks 4 to 6. Conclusion: NPIs implemented during the early phase of the COVID-19 pandemic influenced PICU utilisation and reduced non-SARS-CoV-2 viral infections. Quantitative estimates of such impacts can inform surge capacity planning and the time-limited implementation of NPIs in future pandemics.