Identifying risk factors and patterns for unplanned readmission to a general medical service.

Objective To identify factors and patterns associated with 7- and 28-day readmission for general medicine patients at a tertiary public hospital. Methods A retrospective observational study was conducted using an administrative database at a general medicine service in a tertiary public hospital between 1 January 2007 and 31 December 2011. Demographic and clinical factors, as well as readmission patterns, were evaluated for the association with 7- and 28-day readmission. Results The study cohort included 13802 patients and the 28-day readmission rate was 10.9%. In multivariate analysis, longer hospital stay of the index admission (adjusted relative risk (ARR) 1.34), Charlson index 3 (ARR 1.28), discharge against medical advice (ARR 1.87), active malignancy (ARR 1.83), cardiac failure (ARR 1.48) and incomplete discharge summaries (ARR 1.61) were independently associated with increased risk of 28-day readmission. Patients with diseases of the respiratory system, neurological or genitourinary disease, injury and unclassifiable conditions were likely to be readmitted within 7 days. Patients with circulatory and respiratory disease were likely to be readmitted with the same system diagnosis. Conclusion Readmission of general medicine patients within 28 days is relatively common and is associated with clinical factors and patterns. Identification of these risk factors and patterns will enable the interventions to reduce potentially preventable readmissions. What is known about the topic? Readmission rates following hospitalization are increasing, especially among older patients and those with multiple underlying medical comorbidities. This presents a challenging and costly problem. What does this paper add? Factors associated with increased risk of early readmission include higher comorbidity score, longer length of stay during the index admission and those who discharge against medical advice. Patients with respiratory, neurological or genitourinary disease, trauma and unclassifiable diagnosis were most at risk of early readmission. A large proportion of readmissions had principal diagnoses in a different diagnostic category to that of the index hospitalization. What are the implications for practitioners? A breadth of system review is required before discharging any general medical patient. Intervention should be directed at a breadth of diagnoses and not just the principal diagnosis made during the index admission. Timing of implementation of the interventions is important and more urgent for some diagnoses than others.