OBJECTIVES : COVID-19 can result in severe respiratory illnesses, most notably ARDS. ARDS develops from multiple aetiologies, with no effective treatments outside ventilation. Our objective was to estimate the US population affected by ARDS annually and define the clinical burden.

METHODS : Two approaches were used to estimate the incidence and clinical burden. First, a targeted literature review (TLR) was conducted from a ‘top-down’ approach to obtain the incidence and burden of ARDS defined in previous studies. Secondly, a ‘bottom-up’ approach was used by creating an epidemiological model in Microsoft Excel®, estimating the number of ARDS patients by aetiology. Congruent results between methods established internal consistency.

RESULTS : In the TLR, 16.1% of acute respiratory failure patients were clinically diagnosed with ARDS, translating to 220,496 annual US cases. Low clinician recognition of ARDS was confirmed in one large-scale observational study, reporting that 21.5% of all ICU patients fulfilled ARDS criteria, increasing the estimate to 621,795 ARDS cases requiring ventilation. ARDS was typically diagnosed within two days of hospitalization, and 85% were intubated upon admission to intensive care. With the ‘bottom-up’ approach, 98,276 pneumonia patients, 118,979 sepsis patients, and 13,327 other aetiology (aspiration and trauma) patients were diagnosed annually with ARDS, totalling 230,582. As only 34% of ARDS cases are appropriately diagnosed (Bellani et al., 2017), the estimate increased to 630,616 annual cases, indicating congruent results between methods. Current studies indicate over 40% of hospitalized COVID-19 patients have ARDS, and 20% to 30% required ventilation.

CONCLUSIONS : The incidence of ARDS is substantial, with over 600,000 estimated cases in the US per year, 85% of which require mechanical ventilation. With the rapid spread of COVID-19, this burden has grown considerably. Additional treatment options that are effective in patients presenting with ARDS could result in significant savings from decreased ventilator use, hospitalization, and healthcare resources.