National incidence rates for Acute Respiratory Distress Syndrome (ARDS) and ARDS cause-specific factors in the United States (2006-2014)

Purpose: To estimate the incidence of Acute Respiratory Distress Syndrome (ARDS) and ARDS-related mortality rates. Methods: We identified patients with a risk factor for ARDS in the National Inpatient Sample (NIS) (2006-2014). Using survey-weighted descriptive statistics we estimated annual and overall proportions of ARDS cases. Results: From over 69 million discharges, 1,151.969 ARDS discharges and 969,567 ARDS discharges with a risk factor were identified. Sepsis (46.8%), pneumonia (44.9%) and shock (44.4%) were the most common ARDS risk factor. Pancreatitis (3.4%), pulmonary contusion (1.4%) and drowning (0.2%) were the least frequently reported. Incidence rates increased from 180.7 (2006) to 220.8 (2011) and again from 182.8 (2012) to 193.4 (2014). Incidence for pneumonia, shock and sepsis-associated ARDS increased steadily, while transfusion and trauma-associated ARDS declined. Trends for gastric aspiration and pancreatitis-related ARDS remained unchanged. Shock, sepsis and transfusion-associated ARDS had higher mortality rates compared to other factors. Except for transfusion and trauma-associated ARDS, mortality rates for other factors declined. Conclusion: Although increasing incidence for ARDS was observed, mortality rates declined for most risk factors. Mortality for transfusion and trauma-associated ARDS increased in the later study period, research is needed to examine reasons for the increasing in-hospital deaths associated with these risk factors. Published by Elsevier Inc.