Do countries or hospitals with longer hospital stays for acute heart failure have lower readmission rates?: Findings from ASCEND-HF.

BACKGROUND Hospital readmission is an important clinical outcome of patients with heart failure. Its relation to length of stay for the initial hospitalization is not clear. METHODS AND RESULTS We used hierarchical modeling of data from a clinical trial to examine variations in length of stay across countries and across hospitals in the United States and its association with readmission within 30 days of randomization. Main outcomes included associations between country-level length of stay and readmission rates, after adjustment for patient-level case mix; and associations between length of stay and readmission rates across sites in the United States. Across 27 countries with 389 sites and 6848 patients, mean length of stay ranged from 4.9 to 14.6 days (6.1 days in the United States). Rates of all-cause readmission ranged from 2.5% to 25.0% (17.8% in the United States). There was an inverse correlation between country-level mean length of stay and readmission (r=-0.52; P<0.01). After multivariable adjustment, each additional inpatient day across countries was associated with significantly lower risk of all-cause readmission (odds ratio, 0.86; 95% confidence interval, 0.75-0.98; P=0.02) and heart failure readmission (odds ratio, 0.79; 95% confidence interval, 0.69-0.99; P=0.03). Similar trends were observed across US study sites concerning readmission for any cause (odds ratio, 0.92; 95% confidence interval, 0.85-1.00; P=0.06) and readmission for heart failure (odds ratio, 0.90; 95% confidence interval, 0.80-1.01; P=0.07). Across countries and across US sites, longer median length of stay was independently associated with lower risk of readmission. CONCLUSIONS Countries with longer length of stay for heart failure hospitalizations had significantly lower rates of readmission within 30 days of randomization. These findings may have implications for developing strategies to prevent readmission, defining quality measures, and designing clinical trials in acute heart failure. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00475852.