Correlation between subjective and objective cognitive function in post-intensive care patients: a dual-center prospective cohort study

Abstract

Objectives: To evaluate the correlation between a subjective and objective cognitive screening tool in intensive care unit (ICU) survivors three months post-discharge, and to explore differences in associated factors. Research design: Prospective cohort study. Setting: Two Dutch university ICUs. Main outcome measures: Correlation between subjective (Cognitive Failure Questionnaire [CFQ-14]) and objective (modified Telephone Interview for Cognitive Status [TICS-m]) cognitive function scores and associated clinical and demographic factors. Results: Among 372 included patients (July 2020-July 2022), 20.1 % (n = 75) had cognitive impairment (based only on a CFQ-14 score ≥43, n = 19 (5.1 %); based only on a TICS-m score ≤33, n = 52 (13.9 %); meeting both criteria, n = 4 (1.1 %)). CFQ-14 and TICS-m scores were weakly correlated (r = −0.11, p = 0.03). Using multivariable linear regression, depression scores (Hospital Anxiety and Depression Scale) were significantly associated with standardized CFQ-14 scores (adjusted β 0.16; 95%CI 0.09–0.24; p < 0.01), whereas age (adjusted β −0.03; 95%CI −0.04–−0.01; p < 0.01) and sedation-induced coma (adjusted β −0.49; 95%CI −0.91–−0.07; p = 0.02) were significantly associated with standardized TICS-m scores. Conclusion: Subjective cognitive complaints do not reliably correspond with objective cognitive impairment, and vice versa. Depression scores were associated with subjective cognition, whereas age and sedation-induced coma were associated with objective cognition. Implication for clinical practice: Nurses and physicians, particularly in post-ICU clinics, should be mindful that subjective and objective cognitive screening tools, although both valuable, adress different aspects and should not be considered interchangeable. Self-reported cognitive problems may be driven by emotional distress (e.g., depressive symptoms) rather than objective cognitive impairment.