Impact of sleep apnoea on 30 day hospital readmission rate and cost in heart failure with reduced ejection fraction

AIMS: In this study, we estimated the 30 day all‐cause and heart failure‐specific readmission rates, predictors, mortality, and hospitalization costs in patients with obstructive sleep apnoea admitted with acute decompensated heart failure with reduced ejection fraction. METHODS AND RESULTS: This is a retrospective cohort study using the Agency of Healthcare Research and Quality's National Readmission Database for the year 2019. The primary outcome was the 30 day all‐cause hospital readmission rate. The secondary outcomes were (i) in‐hospital mortality rate for index admissions; (ii) 30 day mortality rate for index hospitalizations; (iii) the five most common principal diagnosis for readmission; (iv) readmission in‐hospital mortality rate; (v) length of hospital stay; (vi) independent risk factors for readmission; and (vii) hospitalization costs. We identified 6908 hospitalizations that met our study definition. The mean patient age was 62.8 years, and women comprised only 27.6% of patients. The 30 day all‐cause readmission rate was 23.4%. 48.9% of readmissions were due to decompensated heart failure. The in‐hospital mortality rate during readmissions was significantly higher than that of the index admission (5.6% vs. 2.4%; P < 0.05). The mean length of stay for patients during index admissions was 6.5 days (6.06–7.02), while during readmissions, it was 8.5 days (7.4–9.6; P < 0.05). The mean total hospitalization charges at index admissions were $78 438 (68 053–88 824), while during readmissions, they were higher at $124 282 (90 906–157 659; P < 0.05). The mean total cost of hospitalization during index admissions was $20 535 (18 311–22 758), while at readmissions, it was higher at $29 954 (24 041–35 867; P < 0.05). The total hospital charges for all 30 day readmissions were $195 million, and total hospital costs was $46.9 million. The variables found to be associated with increased rate of readmissions were patients with Medicaid insurance, higher Charlson co‐morbidity Index, and longer length of stay. The variables associated with lower rate of readmissions were prior percutaneous coronary intervention and patients with private insurance. CONCLUSIONS: In patients with obstructive sleep apnoea admitted with heart failure with reduced ejection fraction, we found a substantial all‐cause readmission rate of 23.4% with heart failure readmission constituting about 48.9% of readmissions. Readmissions were associated with higher mortality and resource use.