Risk factors for unplanned hospital re-admissions: a secondary data analysis of hospital discharge summaries

To identify patient groups at risk for unplanned hospital re-admissions and risk factors for re-admission.

We analysed the Belgian Hospital Discharge Dataset including data from 1 130 491 patients discharged in 2008. Patient and hospital factors contributing to re-admission rate were analysed using a multivariable model for logistic regression.

The overall unplanned re-admission rate was 5.2%. Cardiovascular and pulmonary diagnoses were the most common reasons for re-admission. We found that 10.4% of all re-admissions were due to complications. A high number of previous emergency department (ED) visits proved to be a predictor for re-admission [odds ratio (OR) for patients with at least four ED visits in the past 6 months 4.65; 95% confidence interval (CI) 4.25-5.08]. Patients discharged on Friday (OR 1.05; 95% CI 1.01-1.08) and patients with a long length of stay (OR 1.19; 95% CI 1.15-1.23) also had a higher risk for re-admission. Patients with short lengths of stay were not at risk for re-admission (OR 0.99; 95% CI 0.95-1.02).

Actions to reduce re-admissions can be targeted to patient groups at risk, and should be aimed at the caring for chronic cardiovascular or pulmonary diseases, preventing complications and multiple ED visits, and ensuring continuity of care after discharge, especially for patients discharged on Friday.