RESULTS: In 2011, 1,942,429 emergency room (ER) visits were recorded with a primary diagnosis of asthma resulting in 326,585 (16.8%) hospitalizations and 1,039 (0.32%) deaths. 55,915 patients developed respiratory failure. A greater proportion of women were admitted to the hospital compared to men (205,259 vs. 121,317; p = 0.0003). Asthma mortality was higher in women than in men across all age groups (685 vs. 354; p = 0.003). Asthma mortality was independently associated with age (OR: 1.03; 95% CI 1.02-1.04 per year), number of chronic illnesses (OR: 1.12; 95% CI 1.10-1.14 per comorbidity) and weekend admission (OR: 1.39; 95% CI 1.05-1.84). A restricted cubic spline model with 3 knots was fitted to describe the nonlinear relationship between age and risk for hospitalization and respiratory failure, which were highest among children and older adults. Asthma hospitalization was associated with the number of chronic illnesses (OR: 1.56; 95% CI 1.55-1.57), GERD (OR: 1.32; 95% CI 1.27-1.38) and socioeconomic conditions. Hospitalization risk was higher in Medicaid as compared to Medicare beneficiaries (OR: 1.3; 95% CI 1.25-1.35) and in zip-codes with lower income. The ER charges (Median [IQR]: $295[778; 2092]) increased linearly with patient age. They were higher in women (Median [IQR]: $1354 [811; 2220]) as compared to men (Median [IQR]: $1234[761; 1939]) across all ages (p<0.001). Median hospital charges were higher in women as compared to men ($15,267 vs. $11,807).