Socioeconomic inequalities have been associated with adverse outcomes in critically ill COVID-19 patients. Whether these disparities extend to the most severe ARDS patients treated with ECMO, regardless of etiology, remains uncertain. We aimed to compare the socioeconomic profiles, management, and outcomes of COVID-19 ARDS patients on ECMO with those treated for ARDS due to other causes, using the nationwide French healthcare database.

From March 2015 to December 2021, 1722 adults received ECMO for acute respiratory failure: 1245 with COVID-19, 107 with influenza, and 370 with other causes. Overall, 27% lived in the most deprived neighborhoods, with consistent overrepresentation across etiologies (26.8% COVID-19, 29% influenza, 25.3% other) compared to less deprived neighborhoods (p = 0.039). In-hospital mortality was 56% in COVID-19, 48% in influenza, and 60% in other causes (p = 0.080). Median ICU stay was longest in COVID-19 survivors (56 [36–78] days), who also required longer ECMO support and experienced more complications. Independent predictors of in-hospital death included older age and need for renal replacement therapy at ECMO initiation, while socioeconomic deprivation was not associated with outcomes. After adjustment, mortality was higher in non-COVID-19, non-influenza patients compared with influenza (Odds ratio 1.70, 95% confidence interval [1.03–2.81]).

Severe ARDS requiring ECMO disproportionately affected patients from socioeconomically deprived areas, irrespective of etiology. However, deprivation was not linked to worse outcomes.