Differential impact of the pandemic first wave on chronic respiratory diseases in France

INTRODUCTION: The COVID-19 pandemic has been associated with dramatic changes in the management of patients with chronic respiratory diseases (CRD), resulting in varying clinical profile and use of healthcare services of patients hospitalised. METHODS: Using the French national hospital database, we analysed changes in epidemiological profile, clinical presentation at hospital referral and outcomes (critical care unit, CCU, admission; and in-hospital mortality) of CRD patients hospitalised for COVID-19 during the first wave of the pandemic in France. RESULTS: Structural lung diseases and pulmonary vascular diseases (PVD) were the most prevalent CRDs (93%). The part of CRD patients among the total inpatients was substantial, decreasing during lockdown (from 26.5% to 23.8%), then returning to the pre-lockdown level (27.2%). The CRD patients were older and comorbid males with higher rates of CCU admission and mortality, as compared with their counterparts. Half of them had a complicated clinical profile (CCP: CCU admission or death). Overall, in-hospital length of stay was 9 (4-16) days and mortality rate 19.8%. These characteristics varied along time. In multivariable analyses, PVD and interstitial lung diseases were associated with a CCP (aORs, from 1.34; CI 1.16-1.55 to 1.78; CI 1.52-2.10); PVD was also associated with mortality (with aHRs > 1.5 in the 18-55 and 56-75 age groups). CONCLUSION: We report a substantial part of CRD inpatients with COVID-19, characterised by a more severe initial clinical presentation and higher rates of complicated stays, with changes along time suggesting differential exposure and use of resources. The PVD subgroup was independently associated with a complicated outcome during the entire study period.