Development and Validation of the ReTos Scale as a Support Tool for Fall Risk Assessment in a Large Sample of Older Italian Inpatients

: Aim of this study was to develop and evaluate the validity and reliability of the ReTos (Regione Toscana) scale for identifying older inpatients at risk of falls. 15,159 inpatients aged ≥65 years from 41 Italian hospitals were enrolled with six-month follow-up. Items were generated through literature review and expert consensus. Content validity was assessed by a multidisciplinary panel. Exploratory factor analysis (EFA) examined dimensionality. Internal consistency was estimated using McDonald's Omega. Criterion-related validity was tested through logistic regression, and discriminative performance assessed using the area under the ROC curve. Mean age was 79 years (52.7% female). During follow-up, 278 patients experienced at least one fall (incidence 0.59 per 1,000 patient-days). EFA reduced the original 22 items to 11 items across five factors: motor disorders, mental state, diseases/medications, anamnesis and sensory impairment. Several items were significantly associated with fall occurrence. Internal consistency was acceptable (Ω = 0.79). Discriminative performance was modest (AUC = 0.62; 95% CI 0.58-0.66), with sensitivity 0.70 and specificity 0.52 at a cut-off ≥7; positive predictive value was low (0.03), reflecting low event incidence. The ReTos scale demonstrated satisfactory psychometric properties but modest discriminative performance, supporting its use as an adjunct to clinical judgment rather than a stand-alone tool.