In the present study with ICU survivors interviewed 24 months after discharge, we observed a decline in physical functional status as measured by the Karnofsky and Lawton-IADL scales, especially in patients with neurological diagnoses or trauma, age
65 years or 8 days or more on mechanical ventilation.
Nearly all patients with chronic critical illness leave the hospital with profound impairment of physical function, cognitive status, or both, requiring institutional care [27
]. A systematic review of the literature showed that functional impairment is closely associated with age and disease severity [29
]. After ICU discharge, elderly patients have been observed to require more assistance than younger counterparts to perform tasks such as using public transportation, shopping, and doing the laundry [3
]. Our study confirmed this loss of ability to perform independently in patients aged
Conversely, whereas elderly patients often had good PFS or perceived their PSF as better than before critical illness, trauma patients, who were usually healthy and young before ICU admission [23
], may experience a substantial decline in PFS after the trauma, both in physical and psychosocial dimensions [31
]. Delusional memories, depression [32
], and the inability to return to work negatively [33
] influenced their perceived quality of life. Our study confirmed that trauma decreases the ability to perform activities independently by 2.8 times, and increases the level of dependency by 2.7 times.
The need for prolonged intensive care may also affect prognosis in terms of the ability to perform ADL [34
]; previous articles [35
] have reported that the inability to independently perform activities of daily living is a major factor affecting health-related quality of life (HRQoL) in ICU survivors. In that sense, prolonged MV appears to reduce life quality and expectancy in the long term [34
]. Our study demonstrated that the use of MV for 8 or more days reduced the ability to perform ADL by 1.48 times. According to some authors, 5% to 20% of ICU patients receive MV, and 25% require MV for more than seven days [39
]. In our study, 29.5% required MV and 21.8% of these received ventilatory support for more than eight days.
In our paper, patients with medical and unplanned surgical admissions had decreased PFS; however, this finding did not necessarily imply a reduction in the patients’ actual ability to perform ADLs. Orwelius et al. [40
] suggested that pre-existing disease is the most important factor for long-term HRQoL after critical illness, and not the factors related to ICU-stay. This was not true for our patients, in whom the presence of pre-existing disease had less impact on PFS than prolonged MV and type of ICU admission (neurological and trauma patients).
Many studies refer to quality of life instead of functional status. HRQoL is a broad concept, which encompasses the ability to perform ADL [24
]. In this study, two scales were used in the assessment of PFS, so as to increase the reliability of our results. The Karnofsky index (emphasizing the physical performance and dependency) was chosen because it covers more general aspects of the ability to perform ADL and because it is easy to interpret. Functional impairment has a direct impact on HRQoL because it limits autonomy and physical and mental abilities [13
]. Future studies should also address other issues in relation to PFS, such as cognitive impairment, sleep disturbances, post-traumatic stress disorder, the rehabilitation process, employment status, and cultural and payment differences, can influence quality of life in a less tangible way than, for example, physical impairments after major trauma.
Studies assessing HRQoL after ICU suggest that ICU patients do not return to the same level of health that they had before they fell ill [23
], and that their HRQoL is lower than that of the general population, at least in the early years [3
]. According to Oeyen et al. [23
], a follow-up of 12 or 24 months is probably the best to capture changes that have a negative impact quality of life after intensive care.
The strengths of present study include a large sample (n
499), the fact that possible seasonal variations were accounted for (all admissions in one-year), and a long follow-up period (two-years), in addition to the combined use of two scales to increase the reliability of results and a low rate of individuals lost to follow-up (2.9%). However, some limitations must also be addressed: (a) the interviews were conducted by phone and not face-to-face with the patients. However, 26 of the 53 authors cited by Oeyen et al. [23
] also conducted telephone interviews; (b) only physical functional status, and not HRQoL, was measured; (c) the fact that some interviews were answered by proxies. However, the literature varies concerning the effect of using proxies. Some authors suggest that proxies (next-of-kin) may underestimate quality of life in their relatives [18
]; (d) finally, the present population included many patients with cardiovascular problems and elective surgery, that is, a group of not very sick patients that may not reflect the usual critical care group of patients. Therefore, the present results may not allow generalization.