Abstract 3550: Temporal Trends, Risk Factors, and Hospital Costs of the Adult Respiratory Distress Syndrome (ARDS) after Acute Ischemic Stroke in the United States

Abstract

Background. We sought to determine the prevalence and risk factors of ARDS, and its impact on hospital length of stay (LOS) and cost, after acute ischemic stroke (AIS) in the U.S. Methods. Data were derived from the National Inpatient Sample from 1998-2008. We searched for admissions of patients >18 years, with a diagnosis of AIS and ARDS. Definitions were based on ICD9-CM codes. Prevalence proportions, and hospital LOS and cost were calculated. Multivariate logistic regression models were then fitted to determine odds ratios (OR) and 95% confidence intervals (CI) for determinants of ARDS and to assess for its impact on hospital LOS and cost. Results. Over the 10-year period, we identified 4,066,043 admissions that corresponded to a primary diagnosis of AIS of which 157,464 had ARDS for a cumulative prevalence of 4%. Cases of ARDS after AIS increased from 13,395 (3.6%) in 1998 to 17,222 (4%) in 2008. ARDS was more common among old (OR 0.9; 95%CI 0.9-0.98), men (OR 1.2; 95%CI 1.2-1.21), blacks (OR 1.2; 95%CI 1.1-1.2), urban-academic centers (OR 1.4; 95%CI 1.3-1.5); and in sepsis (OR 8.0; 95%CI 7.6-8.4), cardiovascular dysfunction (OR 3.5; 95%CI 3.3-3.7), respiratory dysfunction(OR 2.3; 95%CI, 2.2-2.4), hepatic dysfunction (OR 2.9; 95%CI 2.4-3.4), hematological dysfunction (OR 1.9; 95%CI, 1.8-2.1), and after thrombolysis (OR 3.8; 95%CI, 3.6-4.0). The median hospital LOS for ARDS was 8 days Inter-Quartile range [IQR] 14-23 vs. 3 days IQR 5-7, p<0.001. Median hospital cost for ARDS was $56,990 IQR $29,360-$111,900 vs. $17,240 IQR $10,760-$28,620, p<0.001. ARDS independently predicted higher hospital LOS (OR 2.4, 95% CI, 2.4-2.5) and higher costs (OR 2.6, 95% CI 2.5-2.6). Conclusion. Our analysis demonstrates an increase in the prevalence of ARDS after AIS in U.S. ARDS is associated with significant increase in hospital LOS and overall costs.