The 3D/3D+ model: A real-world approach to frailty in emergency care.

Population ageing has substantially transformed the profile of patients presenting to emergency departments, with an increase in clinical complexity characterized by frailty, functional and cognitive impairment, multimorbidity, and social vulnerability. Traditional care models, mainly focused on biomedical diagnosis, are limited in addressing this complexity, and existing screening tools usually assess isolated dimensions, thereby restricting their usefulness for clinical decision-making. The 3D/3D+ model was developed as a geriatric assessment tool designed to integrate both baseline status and the impact of the acute episode. Its development followed a hybrid effectiveness-implementation approach and was validated through observational studies including patients aged 75 years or older. The baseline component enabled frailty stratification with high concordance with reference scales, whereas the dynamic component identified the acute impact and was independently associated with mortality and adverse outcomes. Overall, the model demonstrates clinical validity, reproducibility, and practical utility for optimizing care decisions in Emergency Department (ED).