Frailty in Patients With Trauma Who Are Critically Ill: A Prospective Observational Study to Determine Feasibility, Concordance, and Construct and Predictive Validity of 2 Frailty Measures

BACKGROUND: As the older population increases, more older people are exposed to trauma. Frailty can be used to highlight patients at risk of a poorer outcome. OBJECTIVE: The objectives of this study were to compare 2 frailty measures with regard to concordance, floor and ceiling effects, and construct and predictive validity and to determine which is more valid and clinically applicable in a critically ill trauma population. DESIGN: This was a prospective observational study. METHODS: Patients were included if admitted to an intensive care unit (ICU) under a trauma medical unit and ≥ 50 years old. Frailty was determined using 2 frailty measures, the Frailty Phenotype (FP) and Clinical Frailty Scale (CFS). RESULTS: One hundred people were enrolled; their mean age was 69.2 years (SD = 10.4) and 81% had major trauma (as determined with the Injury Severity Score). Frailty was identified with the FP in 22 participants and with the CFS in 13 participants. The 2 frailty measures had an excellent correlation (Spearman rank correlation coefficient = 0.77; 95% confidence interval = 0.66-0.85). Both the FP and the CFS had large floor effects but no ceiling effects. The FP and CFS showed construct validity, with frailty being significantly associated with increasing age, requiring an aid to mobilize, and more falls and hospital admissions. Frailty on the FP was predictive of ICU and hospital mortality, whereas frailty on the CFS was predictive of hospital mortality. LIMITATIONS: The limitations of this study include the use of a single site, small sample size, and collection of frailty measures retrospectively. CONCLUSIONS: Measuring frailty in a trauma ICU population was feasible, with excellent correlation between the 2 frailty measures. Both showed aspects of construct and predictive validity; however, the FP identified frailty in more participants and was associated with more comorbidities and higher mortality at ICU discharge. Therefore, the FP might be more clinically relevant in this population.