Predictors of unplanned 30-day hospital readmission: a retrospective cohort study in north-east Italy

Objective Unplanned hospital readmissions within 30 days of discharge measure the quality of healthcare. This study aims to identify the characteristics of patients at higher risk of readmission. Design Retrospective cohort study. Setting North-east Italy (Marca Trevigiana Local Health Authority). Data source The study examined a total of 39 467 index admissions from hospital discharges (SDO) in the 890 000-inhabitant area during 2022. Outcome measure Readmission rates and 95% CIs were computed by risk factor, age and type of admission (surgical or medical). A logistic mixed-effects model was used to estimate readmission OR, adjusting for potential confounders. Results A total of 2197 readmissions occurred within 30 days of the index admission, resulting in an overall rate of 30-day readmissions of 6.7% (CI 6.4% to 7.0%). The median time to readmission was 11 days (IQR 5 to 20). In the multivariate analysis, after adjusting for age and sex, the following clinical conditions were associated with a higher risk of readmission: alcohol-related disease (OR=2.06, CI 1.36 to 3.13), metastatic cancer (OR=1.98, CI 1.57 to 2.50), epilepsy (OR=1.93, CI 1.36 to 2.75), dialysis or end-stage kidney disease (OR=1.92, CI 1.39 to 2.66), chronic obstructive pulmonary disease (OR=1.88, CI 1.49 to 2.36), stoma (OR=1.72, CI 1.22 to 2.44), transplant (OR=1.62, CI 1.03 to 2.55), being bedridden (OR=1.57, CI 1.28 to 1.93), anaemia (OR=1.57, CI 1.35 to 1.83), urinary tract infection (OR=1.54, CI 1.30 to 1.83), pneumonia (OR=1.52, CI 1.31 to 1.75), dementia (OR=1.49, CI 1.24 to 1.79), diabetes (OR=1.37, CI 1.17 to 1.61) and transfusion (OR=1.34, CI 1.03 to 1.73). Conclusion Several chronic and acute conditions at index admission significantly increased the risk of readmission. Strengthening transitional care, outpatient services and palliative care could mitigate readmissions.