Abstract & Commentary
Frailty: An Important Determinant of Outcome in Critical Illness
By David J. Pierson, MD, Editor
SYNOPSIS: In this prospective study of older ICU patients (mean age, 67 years), frailty as assessed by a simple scale was present in one-third and was strongly associated with increased risk of adverse events, morbidity, and mortality.
- SOURCE: Bagshaw SM, et al. Association between frailty and short- and long-term outcomes among critically ill patients: A multicentre prospective cohort study. CMAJ 2014;186:E95-102.
Frailty is an age-associated loss of reserve across multiple physiologic and cognitive systems that leads to increased susceptibility to adverse events. This prospective cohort study carried out in six hospitals in Alberta evaluated all patients aged ≥ 50 years who were admitted to an ICU during an 18-month period for the presence of frailty using a simple, validated scale. The purpose was to determine the prevalence, correlates, and outcomes associated with frailty in this population. With informed consent, patients were enrolled if they were expected to remain in the ICU for at least 24 hours and had not previously participated in the study. Patients were considered to be frail if they had a score > 4 on the Clinical Frailty Scale1 (see Table), as of just prior to hospitalization.
Of 1359 potentially eligible patients during the study period, 421 were enrolled, all of whom were assessed during the hospitalization and at 6 and 12 months. Their mean age was 67 ± 10 years, 39% were female, and 95% were living at home (independently or with assistance) prior to admission. One hundred thirty-eight patients (32.8%) met the frailty criteria and 283 were not frail. Compared to non-frail patients, frail patients were older, more likely to be female, had more comorbid disease and greater functional dependence, and tended to have fewer social supports.
Mortality in the ICU did not differ according to frailty, but frail patients had higher in-hospital mortality (32% vs 16%; odds ratio [OR], 1.81; 95% CI, 1.09-3.01). With multivariable analysis controlling for age, sex, comorbidities, APACHE II score, and Sequential Organ Failure Assessment (SOFA) score during the 12-month follow-up period, frailty was independently associated with all-cause mortality (48% vs 25%; hazard ratio, 1.82; 95% CI, 1.28-2.60). When the absolute frailty score was used rather than the 4-point cutoff, an increasing frailty score was independently associated with incremental mortality. Surviving patients who were frail were less likely to be living independently at home (22% vs 44%; OR, 0.35; 95% CI, 0.20-0.61), a difference that persisted through the 12-month follow-up. Health-related quality of life at 6 and 12 months was generally lower in all domains among patients who were frail, although both groups had lower scores than expected for the general population of the province.
|
Frailty Score |
Category |
Description |
1 |
Very fit |
Robust, active, energetic, motivated; commonly exercise regularly; among the fittest individuals for their age |
2 |
Well |
No active disease symptoms but less fit than in category 1; exercise or are very active only occasionally (e.g., seasonally) |
3 |
Managing well |
Medical problems well controlled, but not regularly active beyond routine walking |
4 |
Vulnerable |
Not dependent on others for daily help but symptoms often limit activities; frequently "slowed up" or tired during the day |
5 |
Mildly frail |
More evident slowing, needing help in high-order activities of daily living such as finances, transportation, heavy housework, and medications; somewhat impaired with respect to shopping, walking outside alone, meal preparation, and housework |
6 |
Moderately frail |
Need help with all outside activities and with housekeeping; often have trouble with stairs and need help with bathing; might need minimal assistance (cuing, standby) with dressing |
7 |
Severely frail |
Completely dependent for personal care, from whatever cause (physical or cognitive), but seem stable and not at high risk of dying (for example, within 6 months) |
8 |
Very severely frail |
Completely dependent, approaching the end of life; recovery from even a relatively minor illness unlikely |
9 |
Terminally ill |
Approaching the end of life; category also applies to persons with life expectancy < 6 months but not otherwise evidently frail |
*from Rockwood K, et al. A global clinical measure of fitness and frailty in elderly people. CMAJ 2005;173:489-495. |
COMMENTARY
Frailty is an aspect of health status that has received little attention in critical care. However, it is easy to assess on ICU admission (see Table), and this well-done study shows that it is strongly associated with morbidity and mortality —independently of age, comorbidities, and other variables commonly used in evaluating prognosis. As the authors point out, "the interplay of frailty and critical illness may provide an opportunity to target and evaluate interdisciplinary programs of care and rehabilitation, with the aim of improving recovery and avoiding mortality, functional dependence, reduced quality of life and added health service utilization." Aspects of critical care such as minimization of sedation, screening for delirium, nutritional support, early assessment for ventilator weaning, aggressive mobilization, and other areas currently receiving increased attention may be especially important in patients who are frail. Routine detection of frailty when present on ICU admission, and its inclusion in care-related decision-making for patients and their families, may facilitate the setting of goals of care and other aspects of management.
REFERENCE
1. Rockwood K, et al. A global clinical measure of fitness and frailty in elderly people. CMAJ 2005;173:489-495.
