Social inequalities in ICU admission for COPD exacerbations: Insights from a matched case-control study

BACKGROUND: Exacerbations of Chronic Obstructive Pulmonary Disease (COPD) often result in hospitalizations and Intensive Care Unit (ICU) admissions. Although clinical predictors of ICU admission are well described, the role of social deprivation is less explored. We evaluated its impact on ICU admission risk among COPD patients admitted to the emergency department for exacerbations. METHODS: We conducted a retrospective, monocentric, matched case-control study at Caen University Hospital (France) between January 2018 and December 2022. COPD exacerbations were identified through ICD-10 coding. Cases were patients hospitalized in ICU; controls were hospitalized in conventional wards. Patients were matched by sex and age (±5 years). The primary exposure was social deprivation measured using a novel ecological index: the French version of the European Deprivation Index (EDI). Each patient's EDI score was categorized into quintiles based on their residential area (1 = least deprived to 5 = most deprived). Multivariable conditional logistic regression was performed, adjusting for confounders. RESULTS: Among 850 patients (321 cases, 529 controls), 57% belonged to the most deprived categories (EDI 4-5). Higher social deprivation (EDI 4-5) (OR 0.54, 95% CI: 0.29-0.98) was associated with lower ICU admission compared to lower social deprivation. Sensitivity analyses using multiple imputation and modelling as five level categorical variable confirmed results. CONCLUSIONS: This study highlights that area-level social deprivation, as measured by the EDI, may negatively influence ICU admission in certain cohorts of COPD patients admitted to the emergency department.