Timing, Diagnosis, and Potential Preventability of 30-Day Unplanned Readmissions After a Heart Failure Hospitalisation: Implications for Care Quality.

Aim: To assess timing, causes, and potential preventability of unplanned readmissions within 30 days of heart failure hospitalisation and how they vary by age and sex across the population.

Method: We conducted a cohort study using hospitalisation data from 2013 to 2017 from all public and most private hospitals in Australia and New Zealand, including 197,648 patients aged ≥18 years (mean age 78.2 [standard deviation 12.3] years, 52.4% male, 13.3% <65 years) with a primary diagnosis of heart failure. The main outcomes included the timing of 30-day unplanned readmissions, the diagnoses associated with these, and their potential preventability. Preventability was determined by categorising readmission diagnoses into the following: 1) potential hospital-acquired complication, 2) recurrent heart failure, 3) clinically related to heart failure, and 4) all other diagnoses. Groups 1 and 2 were deemed most preventable.

Results: A total of 43,011 (21.8%) patients had one or more unplanned readmissions within 30 days. The peak readmission risk occurred on days 2-4 post-discharge with 25,318 (58.9%) occurring within 2 weeks. When grouped, diagnoses consistent with a potential hospital-acquired complication (group 1) accounted for 41.7% (most commonly pneumonia, atrial fibrillation/flutter, and myocardial infarction), readmission for recurrent heart failure (group 2) comprised 38.2%, and groups 3 and 4 consisted of 11.5% and 8.6%, respectively. Although heart failure hospitalisation occurred more frequently in older adults, the risk of readmission exceeded 20% in all age groups, and the timing and potential preventability were not clinically significantly different across age and sex.

Conclusions: The peak risk of unplanned readmission occurred in the first few days after discharge, often for potentially preventable reasons such as hospital-acquired complications and recurrent heart failure. Such early and potentially preventable readmissions suggest many may be related to suboptimal quality of hospital care and discharge practices. Future clinical and policy interventions should target improving hospital-based heart failure care quality to reduce avoidable readmissions.