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.