Identifying core adverse health outcomes for frailty assessment in older adults using administrative data

Objectives: Measurement of frailty can be based on the ability to predict adverse health outcomes. Although frailty research is progressing rapidly, a unique work that analyzes together outcomes related to frailty condition is still lacking in literature. This article aims to fill this gap, selecting a parsimonious set of outcomes relevant in frailty studies that exploit administrative healthcare data. Methods: Starting with an extensive literature review, we identified several health outcomes that can be measured with administrative healthcare databases. We computed the prevalence and correlation of these outcomes in a local health unit in North-East Italy. We performed a factor analysis and estimated a graphical model to examine the conditional independence relationships between the outcomes. Results: Our analysis revealed two primary outcome groups: adverse events (characterized by various forms of hospital use) and adverse conditions (such as dementia and disability). Femur fracture emerged as a distinct outcome, while death showed positive associations with all other outcomes. Considering overlaps and relationships, we selected a core set of six representative outcomes: death, high priority access to the emergency room, femur fracture, hospitalization, disability, and dementia. Conclusion: This study identified six central and non-redundant adverse health outcomes related to frailty that can be easily derived from routinely available administrative healthcare data. These findings provide a methodologically grounded selection of outcomes that are clinically meaningful and feasible, offering a solid foundation for developing population-based frailty indices.