Background: Frailty, a very important complication of increasing age, is a well-recognised concept although it has not been accurately measured in the clinical setting. The aim of this literature review is to summarise commonly used frailty screening tools, and to describe how new measurement methods have been developed recently.
Methods: Several frailty measurement tools including the most cited and newly developed scales have been described in this review. We searched the MEDLINE using the search terms; "frailty score, scale, tool, instrument, index, phenotype" and then summarised selected tools for physical, cognitive, emotional and co-morbidity domains.
Results: The most cited frailty measurement methods developed from 1999 to 2005 are primarily criteria for physical frailty (e.g., frailty phenotype). More recently developed tools (e.g., triad of impairment and multidimensional frailty score) consider cognitive and emotional domains in addition to physical deficit in measuring frailty. Co-morbidity has also been considered as a domain of frailty in several measurement tools.
Conclusion: Although frailty tools have traditionally assessed physical capability, cognitive and emotional impairment often co-exist in older adults and may have shared origins. Therefore, newer tools which provide a composite measure of frailty may be more relevant for future use.
Keywords: cognitive impairment; emotional impairment; frailty; physical deficit.