Long-term cognitive functioning is impaired in ICU-treated COVID-19 patients: a comprehensive controlled neuropsychological study

Abstract

Background: Cognitive impairment has emerged as a common post-acute sequela of coronavirus disease 2019 (COVID-19). We hypothesised that cognitive impairment exists in patients after COVID-19 and that it is most severe in patients admitted to the intensive care unit (ICU). Methods: This prospective controlled cohort study of 213 participants performed at the Helsinki University Hospital and the University of Helsinki, Finland, comprised three groups of patients—ICU-treated (n = 72), ward-treated (n = 49), and home-isolated (n = 44)—with confirmed COVID-19 between March 13 and December 31, 2020, participating in a comprehensive neuropsychological evaluation six months after the acute phase. Our study included a control group with no history of COVID-19 (n = 48). Medical and demographic data were collected from electronic patient records and interviews carried out four months after the acute phase. Questionnaires filled six months after the acute phase provided information about change in cognitive functioning observed by a close informant, as well as the presence of self-reported depressive and post-traumatic symptoms. Results: The groups differed (effect size η2p = 0.065, p = 0.004) in the total cognitive score, calculated from neuropsychological measures in three domains (attention, executive functions, and memory). Both ICU-treated (p = 0.011) and ward-treated patients (p = 0.005) performed worse than home-isolated patients. Among those with more than 12 years of education, ICU-treated patients performed worse in the attention domain than ward-treated patients (p = 0.021) or non-COVID controls (p = 0.045); ICU-treated male patients, in particular, were impaired in executive functions (p = 0.037). Conclusions: ICU-treated COVID-19 patients, compared to patients with less severe acute COVID-19 or non-COVID controls, showed more severe long-term cognitive impairment. Among those with more than 12 years of education, impairment existed particularly in the domains of attention and for men, of executive functions. Trial registration number: ClinicalTrials.gov NCT04864938, retrospectively registered February 9, 2021.