The State of Frailty in Research: A Mapping Review of Its Clinical Applicability to Practice.

Research on frailty has expanded in the last decade, but direct evidence supporting its implementation in clinical practice may be limited. This mapping review synthesizes the contexts-of-use and overall clinical applicability of recent pre-COVID frailty research. We sampled 476 articles from articles published on frailty in PubMed and EMBASE in 2017-2018, of which 150 articles were fully appraised for the contexts-of-use, definitions, and interventions. A clinical applicability framework was used to classify articles as practice-changing, practice-informing, or not practice-informing. Of the 476 sampled articles, 31% (n = 150) used frailty in functions that could inform a clinical indication: predictor or mediator (26%, n = 125), selection criterion (3%, n = 15), and effect modifier (2%, n = 10). Articles spanned all health disciplines, and cohort studies comprised 91% (n = 137) of studies and trials 9% (n = 13). Thirty-eight frailty definitions using varied cut-offs and a wide range of interventions were identified. Among all articles, 13% (n = 63) of articles were practice-informing, 2% (n = 11) potentially practice-changing, and 0.2% (n = 1) clearly practice-changing. Lack of well-defined intervention and identifiable effect (96%) or originality (83%) were predominant reasons reducing applicability. Only a minority of recent frailty research provides direct evidence of applicability to practice. Future research on frailty should focus on translating frailty, as a risk factor, into a clinical indication and address definition ambiguity.