Defining frailty for healthcare practice and research: A qualitative systematic review with thematic analysis

To identify and examine definitions of frailty using qualitative thematic analysis.

A qualitative meta-aggregative systematic review.

The database search was performed using ASSIA, CINAHL, Cochrane Library, Embase, PsycINFO, PubMed and Google Scholar databases. Studies providing definitions of frailty, published in English from 1^st January 2000 to 25^th July 2018 were included.

Data were extracted by independent reviewers for qualitative thematic analysis.

In total, 86 studies met inclusion criteria. Five major themes with specific sub-themes were identified following thematic analysis including: (1) types of definitions (operational, conceptual, theoretical, older adults' perspective); (2) characteristics of frailty (a multi-domain and dimensional state, deficits/decline, weakness, a continuum-dynamic concept, clinically identifiable); (3) associated factors (age, comorbidity, nutrition, sarcopenia, social networks and environment); (4) mechanism (reduced adaptability, hormonal dysregulation); and (5) changes in health status and adverse outcomes (disability, increased risk of mortality, other healthcare related outcomes such as increased dependency or risk of falls).

Several themes were found that defined frailty, focusing predominantly on operational definitions and frailty as a physical syndrome. A universally accepted standard definition, which includes all dimensions of frailty is currently warranted.