Trends, causes and timing of 30-day readmissions after hospitalization for heart failure: 11-year population-based analysis with linked data.

BACKGROUND: Reliable data are necessary if the burden of early readmissions following hospitalization for heart failure (HF) is to be addressed. We studied unplanned 30-day readmissions, their causes and timing over an 11-year period, using population-based linked data.

METHODS: All hospitalizations from 2003 to 2013 were analyzed by using administrative linked data based on the Minimum Basic Set discharge registry of the Department of Health (Region of Murcia, Spain). Index hospitalizations with HF as principal diagnosis (n=27,581) were identified. Transfers between centers were merged into one discharge. Readmissions were defined as unplanned admissions to any hospital within 30-days after discharge.

RESULTS: In the 2003-2013 period, 30-day readmission rates had a relative mean annual growth of +1.36%, increasing from 17.6% to 22.1%, with similar trends for cardiovascular and non-cardiovascular causes. The figure of 22.1% decreased to 19.8% when only same-hospital readmissions were considered. Most readmissions were due to cardiovascular causes (60%), HF being the most common single cause (34%). The timing of readmission shows an early peak on the fourth day post discharge (+13.29%) due to causes other than HF, followed by a gradual decline (-3.32%); readmission for HF decreased steadily from the first day (-2.22%). Readmission for HF (12.7%) or non-cardiovascular causes (13.3%) had higher in-hospital mortality rates than the index hospitalization (9.2%, p<0.001). Age and comorbidity burden were the main predictors of any readmission, but the performance of a predictive model was poor.

CONCLUSION: These findings support the need for population-based strategies to reduce the burden of early-unplanned readmissions.