Derivation and validation of a 90-day unplanned hospital readmission score in older patients discharged form a geriatric ward

PURPOSE: To derive and validate a 90-day unplanned hospital readmission (UHR) score based on information available to non-hospital based care providers. METHODS: Retrospective longitudinal study with cross-validation method. Participants were older adults (≥ 65 years) admitted to a geriatric short-stay department in a general hospital in France. Patients were split into a derivation cohort and a validation cohort. We recorded demographic information, medical history, and concurrent clinical characteristics. The main outcome was 90-day UHR. Data obtained from hospital discharge letters were used in a logistic regression model to construct a predictive score, and to identify risk groups for 90-day UHR. RESULTS: In total, 750 and 250 aged adults were included in both the derivation and the validation cohorts. Mean age was 87.2 ± 5.2 years, most were women (68.1%). Independent risk factors for 90-day UHR were: use of mobility aids (p = .02), presence of dementia syndrome (p = .02), history of recent hospitalisation (p = .03), and discharge to domiciliary home (p = .005). From these four risk factors, three groups were determined: low-risk group (score < 4), medium-risk group (score between 4 and 6), and high-risk group (score ≥ 6). In the derivation cohort the 90-day UHR rates increased significantly across risk groups (14%, 22%, and 30%, respectively). The 90-day UHR score had the same discriminant power in the derivation cohort (c-statistic = 0.63) as in the validation cohort (c-statistic = 0.63). CONCLUSIONS: This score makes it possible to identify aged adults at risk of 90-day UHR and to target multidisciplinary interventions to limit UHR for patients discharged from a Geriatric Short-Stay Unit.