Impact of frailty on persistent critical illness: a population-based cohort study

Abstract

Purpose: Acute illness severity predicts mortality in intensive care unit (ICU) patients, however, its predictive value decreases over time in ICU. Typically after 10 days, pre-ICU (antecedent) characteristics become more predictive of mortality, defining the onset of persistent critical illness (PerCI). How patient frailty affects development and death from PerCI is unknown. Methods:We conducted a secondary analysis of data from a prospective binational cohort study including 269,785 critically ill adults from 168 ICUs in Australia and New Zealand, investigating whether frailty measured with the Clinical Frailty Scale (CFS) changes the timing of onset and risk of developing PerCI and of subsequent in-hospital mortality. We assessed associations between frailty (CFS ≥ 5) and mortality prediction using logistic regression and area under the receiver operating characteristics (AUROC) curves.Results: 2190 of 50,814 (4.3%) patients with frailty (CFS ≥ 5) versus 6624 of 218,971 (3%) patients without frailty (CFS ≤ 4) developed PerCI (P < 0.001). Among patients with PerCI, 669 of 2190 (30.5%) with frailty and 1194 of 6624 without frailty (18%) died in hospital (P < 0.001). The time point defining PerCI onset did not vary with frailty degree; however, with increasing length of ICU stay, inclusion of frailty progressively improved mortality discrimination (0.1% AUROC improvement on ICU day one versus 3.6% on ICU day 17). Conclusion:Compared to patients without frailty, those with frailty have a higher chance of developing and dying from PerCI. Moreover the importance of frailty as a predictor of mortality increases with ICU length of stay. Future work should explore incorporation of frailty in prognostic models, particularly for long-staying patients.

Chronic critical illness in polytrauma. Results of the Spanish trauma in ICU registry

“…This is interesting for two reasons. First, age can be associated with frailty, a variable that plays a contributing role at the beginning and in the perpetuation of chronicity 29 . Indeed, it is possible that the comorbidities and frailties associated with age are the variables that are really linked to CCI in our study.…”

“…Indeed, it is possible that the comorbidities and frailties associated with age are the variables that are really linked to CCI in our study. A retrospective study has been published showing the correlation of frailty and the probability of developing critical chronic persistent disease, up to double 29 . Our register has no information related to the frailty and therefore we have not been able to evaluate it.…”

“…showing the correlation of frailty and the probability of developing critical chronic persistent disease, up to double. 29 Our register has no information related to the frailty and therefore we have not been able to evaluate it. However, we hypothesize that if we were able to identify vulnerable patients early, specific measures could be intensified.…”

Chronic critical illness – What is it and what can be done about it?

“…Other studies have also alluded to the effect of age on CCI. 7 As a final caution, until there is consensus about what CCI is as a concept and a definition we would not recommend using it as a factor in instituting palliation or withdrawal of therapy. The development and perpetuation of the concept of CCI could soon be one additional tool when making decisions in relation to the adequacy of the therapeutic effort.…”

“…As an indicator of this effect the authors note that the CCI group in their study was in fact older than the control group. Other studies have also alluded to the effect of age on CCI 7 …”