Reliability of frailty assessment in Intensive Care
Research type
Research Study
Full title
Reliability of frailty assessment in Intensive Care
IRAS ID
228370
Contact name
Richard Pugh
Contact email
Sponsor organisation
BCUHB
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
Research Summary
As national populations age, the proportion of older patients among those admitted to Critical Care has risen in many region, though not uniformly so. Age unfortunately has negative prognostic implications for the outcome of critical illness, and if faced with poor likelihood of meaningful survival many older patients may express a wish "not to be kept alive on life support". Given that critical illness may impair an individual's ability to take part in clinical decision-making, family members often play an important role in decisions to admit to critical care and to initiate organ support, but may feel inadequately informed, unsure or conflicted in doing so.
However, age itself is a crude prognostic factor, and the importance of "physiological" as opposed to "chronological" age has long been appreciated by clinicians. "Frailty" is a term used to describe "a condition characterised by loss of biological reserve and vulnerability to poor resolution of homeostasis following a stressor event". The concept of using assessment of frailty as a means of supporting clinicians, patients and their families in clinical decision-making and to predict potential resource requirements is relatively new to critical care.
If frailty assessment tools prove to be valid, reliable and feasible for use in critical care, they may usefully inform discussions with patients, families, and other clinical teams regarding the anticipated benefits of critical care therapies, and the additional rehabilitation needs that critically ill patients identified as frail may require. Although on a population basis frailty appears to be predictive of short- and long-term outcomes, clinimetric properties of frailty assessment tools (as they apply to the critically ill) have to date not been evaluated in depth. Due to the frequency of acute cognitive impairment in critical illness, patients are often unable to contribute fully to frailty assessment and there may be greater reliance on proxies. Furthermore, the views of family members may not necessarily concur with those of the individual patient him- or her- self. Although there is evidence of reliability in other circumstances, it is unclear what degree of concordance there might exist between assessments of frailty by independent clinicians in Critical Care.
As an issue of particular relevance to assessment of the critically ill, the focus of this study will be on the inter-rater reliability of the Clinical Frailty Scale - which at present is the frailty assessment tool best studied in this population - as applied to patients in Critical Care.
Summary of Results
Demand for critical care among older patients is increasing in many countries. Assessment of frailty may help discussions and decision making, but this can be difficult when the subject is critically ill when there is a much greater reliance on people who know the individual well. We wished to study how closely assessments of "frailty" matched for patients admitted to critical care. We conducted a prospective, multi-centre study comparing assessments of frailty (using the "Clinical Frailty Scale" or "CFS") by staff from medical, nursing and physiotherapy backgrounds. Each assessment was made independently by two assessors after review of clinical notes and interview with an individual who maintained close contact with the patient. Frailty was defined as a Clinical Frailty Scale rating > 4. We made 202 assessments in 101 patients. Fifty-two (51%) of the included patients were able to participate in the interview; 35 patients (35%) were considered frail. We found a good level of agreement between assessors overall. However, frailty rating differed by at least one category in nearly half of cases. Factors independently associated with higher frailty ratings were: female sex; severity of illness; greater pre-hospital dependence; and assessments made by doctors. Our study supports use of CFS assessment in critical care, but we found some factors which might suggest an element of personal bias.
REC name
Wales REC 4
REC reference
17/WA/0168
Date of REC Opinion
12 Jun 2017
REC opinion
Favourable Opinion