PURPOSE

Intensive care unit survivors suffer from prolonged impairment, reduced quality of life, and higher mortality rates after discharge compared to the general population. Socioeconomic status may play a partial but important role in mortality and recovery. Therefore, the detection of factors that are responsible for poor long-term outcomes would be beneficial in designing targeted interventions for at-risk populations.

METHODS

For an endpoint analysis, 1834 intensive care unit patients with known French Deprivation Index (FDep) scores were included from the French and euRopean Outcome reGistry in Intensive Care Units (FROG-ICU) study, which was a prospective, observational, multicenter cohort study performed in 20 French intensive care units in 13 different hospitals. Socioeconomic status was defined by using the FDep score [represented as quintiles when referring to the general French population, as quintiles when referring to the FROG-ICU cohort, or as dichotomized data (which was defined as a FDep ≤ 0 for nondeprived patients)] and by using a detailed social questionnaire that was completed 3 months after discharge. The primary outcome included an all-cause, 1-year mortality after ICU discharge when regarding socioeconomic status. The secondary outcomes included both ICU and hospital lengths of stay, both short- and medium-term mortality, and the quality of life, as assessed during the 1-year follow-up by using the Medical Outcome Survey Short Form-36 (SF-36). The Revised Impact of Event Scale (IES-R) was used to evaluate the symptoms of post-traumatic stress disorder, and the Hospital Anxiety and Depression Scale (HADS) was used to screen for anxiety and depression.

RESULTS

Of the 1447 patients who were discharged alive from the ICU, 19.2% died over the following year. No association was found between 1-year mortality and socioeconomic status, regardless of whether this association was analyzed in quintiles (p = 0.911 in the quintiles of the general French population; p = 0.589 in the quintiles of the FROG-ICU cohort itself) or as dichotomized data [nondeprived (n = 177; 1-year mortality of 18.2%) versus deprived (n = 97; 1-year mortality of 20.5%; p = 0.304)]. Moreover, no differences were found between the nondeprived and the deprived patients in the ICU and hospital lengths of stay, ICU mortalities, in-hospital mortalities, or 28-day mortalities. The SF-36 was below the score for the normal French population throughout the follow-up period. Socially deprived patients showed significantly lower median scores in the physical function subscale [55, interquartile range (IQR) (28.8-80) vs. 65, IQR (35-90); p = 0.014], the physical role subscale [25, IQR (0-75) vs. 33.3, IQR (0-100); p = 0.022], and the overall physical component scale [47.5, IQR (30-68.8) vs. 54.4, IQR (35-78.8); p = 0.010]. Up to 31.6% of survivors presented symptoms that indicated post-traumatic stress disorder, and up to 31.5% of survivors reported clinically meaningful symptoms of anxiety or depression.

CONCLUSIONS

A lower socioeconomic status was associated with lower self-reported physical component scores in the nondeprived patients. Psychiatric symptoms are frequently reported after an ICU stay, and subsequent interventions should target those fields.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01367093; registered on June 6, 2011.