Long-term, patient-centered, frailty-based outcomes of older critical illness survivors from the emergency department: a post hoc analysis of the LIFE Study
Authors: Hongo Takashi , Yumoto Tetsuya , Inaba Mototaka , Taito Shunsuke , Yorifuji Takashi , Nakao Atsunori , Naito Hiromichi ,   the LIFE Study Investigators, Nakamichi Chikaaki , Maeyama Hiroki , Ishikawa Hideki , Shime Nobuaki , Uemori Sadayori , Ishihara Satoshi , Takaoka Makoto , Ohtsuka Tsuyoshi , Harada Masahiro , Nozaki Satoshi , Kohama Keisuke , Sakurai Ryota , Sato Shuho , Muramatsu Shun , Yamashita Kazunori , Mayumi Toshihiko , Aita Kaoruko , Mochizuki Satoshi , Itoh Hirofumi , Senda Asase , Otani Kana , Gon Chison , Ohnishi Takeshi , Taguchi Yuji , Miike Toru , Umeda Koki , Kondo Yuji , Arai Takao , Tsurukiri Junya 
Published: March 2024

Abstract
Background
Evidence indicates frailty before intensive care unit (ICU) admission leads to poor outcomes. However, it is unclear whether quality of life (QOL) and activities of daily living (ADL) for survivors of critical illness admitted to the ICU via the emergency department remain consistent or deteriorate in the long-term compared to baseline. This study aimed to evaluate long-term QOL/ADL outcomes in these patients, categorized by the presence or absence of frailty according to Clinical Frailty Scale (CFS) score, as well as explore factors that influence these outcomes.

Methods
This was a post-hoc analysis of a prospective, multicenter, observational study conducted across Japan. It included survivors aged 65 years or older who were admitted to the ICU through the emergency department. Based on CFS scores, participants were categorized into either the not frail group or the frail group, using a threshold CFS score of < 4. Our primary outcome was patient-centered outcomes (QOL/ADL) measured by the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) and the Barthel Index six months post-ICU admission, comparing results from baseline. Secondary outcomes included exploration of factors associated with QOL/ADL six months post-ICU admission using multiple linear regression analyses.

Results
Of 514 candidates, 390 participants responded to the EQ-5D-5L questionnaire, while 237 responded to the Barthel Index. At six months post-admission, mean EQ-5D-5L values declined in both the not frail and frail groups (0.80 to 0.73, p = 0.003 and 0.58 to 0.50, p = 0.002, respectively); Barthel Index scores also declined in both groups (98 to 83, p < 0.001 and 79 to 61, p < 0.001, respectively). Multiple linear regression analysis revealed that baseline frailty (β coefficient, -0.15; 95% CI, − 0.23 to − 0.07; p < 0.001) and pre-admission EQ-5D-5L scores (β coefficient, 0.14; 95% CI, 0.02 to 0.26; p = 0.016) affected EQ-5D-5L scores at six months. Similarly, baseline frailty (β coefficient, -12.3; 95% CI, − 23.9 to − 0.80; p = 0.036) and Barthel Index scores (β coefficient, 0.54; 95% CI, 0.30 to 0.79; p < 0.001) influenced the Barthel Index score at six months.

Conclusions
Regardless of frailty, older ICU survivors from the emergency department were more likely to experience reduced QOL and ADL six months after ICU admission compared to baseline.