Examining the association of social determinants of health on critically ill COVID-19 patient outcomes: a retrospective observational study

Objective: To study the association between air quality index (AQI) and World Health Organization (WHO) Clinical Progression Scale score following Coronavirus disease 2019 (COVID-19) diagnosis. Methods: Retrospective study of adults admitted to intensive care units between January 1, 2020 and March 31, 2022 with positive SARS-CoV-2 test. We used proportional odds regression to study association between average AQI over 12 months prior to COVID-19 diagnosis and highest WHO Clinical Progression Scale score on 28th day following ICU admission. As sensitivity analyses, we studied average AQI over 2 months prior and 2 weeks prior to COVID-19 diagnosis. Results: We identified 1,915 patients with median (IQR) AQI of 37 (33–41). Following regression analysis, a 10-unit increase in average AQI values over the past 12 months prior to COVID-19 diagnosis was associated with reduced odds of having a greater WHO Clinical Progression Scale score (OR 0.84; 95% CI 0.72–0.97; p = 0.02). We failed to detect significant association between AQI and WHO Clinical Progression Scale score (p = 0.26 for 2 months AQI, 0.31 for 2 weeks AQI) within sensitivity analyses. Conclusions: More specific air quality measurements may more accurately identify those at risk for COVID-19 complications following critical illness. Keywords: Air quality index critical illness, COVID-19, intensive care units, World Health Organization