[Frailty at the interface of resilience and intrinsic capacity]

Various concepts are used to assess the health status of geriatric patients, including frailty, resilience, and intrinsic capacity. Frailty, as the oldest and best-known concept among these, focuses on identifying functional deficits, whereas resilience and intrinsic capacity primarily assess preserved abilities. The application of all these concepts supports risk stratification and therapy planning in older patients.

The aim of the present work is to systematically present intrinsic capacity and resilience as well as their relationship to and distinguishing characteristics from frailty. Additionally, intrinsic capacity and resilience are here considered within the framework of specific and overlapping features, as well as differences and practical relevance for geriatric care.

A narrative analysis of the concepts was conducted based on current literature.

Content overlap between frailty, intrinsic capacity and resilience, particularly in the domains of mobility and mental abilities, is present. Since most concepts emphasize only one thematic focus, multidimensional models, such as intrinsic capacity, can be advantageous. Different versions of measurement tools, especially for frailty, exist for different clinical settings. To date, no standardized measurement tools of frailty, intrinsic capacity, and resilience have been universally recommended.

All concepts play an important role in the clinically meaningful stratification of older adults. In clinical practice, it is recommended to select one concept based on the parameters to be evaluated and to apply it consistently across all assessment time points.