ABSTRACT
Background: Understanding the long-term effects of coronavirus disease 2019 (COVID-19) on cognitive function is essential for the prevention of cognitive decline in elderly population. This study aims to assess cognitive status and longitudinal decline at 6 months post-infection in elderly patients recovered from COVID-19.Methods: This cross-sectional study recruited 1013 COVID-19 inpatients aged over 60 years who were discharged from three COVID-19-designated hospitals in Wuhan, China, from February 10 to March 13, 2020. In total, 262 uninfected living spouses of COVID-19 patients were selected as controls. Subjects were examined for their current cognitive status using a Chinese version of the Telephone Interview of Cognitive Status-40 (TICS-40) and longitudinal cognitive decline using an Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). Cognitive assessments were performed 6 months after patient discharge.Findings: COVID-19 patients had significantly lower TICS-40 scores (patients: 29.73±6.13; controls: 30.74±5.95, p=0.016) and higher IQCODE scores (patients: 3.40±0.81; controls: 3.15±0.39, p<0.001) than the controls. Severe COVID-19 patients had lower TICS-40 scores and higher IQCODE scores than non-severe COVID-19 patients (TICS-40: 22.98±7.12 vs. 30.46±5.53, p<0.001; IQCODE: 4.06±1.39 vs. 3.33±0.68, p<0.001) and controls (TICS-40: 22.98±7.12 vs. 30.74±5.95, p<0.001; IQCODE: 4.06±1.39 vs. 3.15±0.39, p<0.001). Severe COVID-19 patients had a higher proportion of cases with a current cognitive impairment and longitudinal cognitive decline than non-severe COVID-19 patients and controls. COVID-19 severity (OR: 8.142, 95% CI: 5.007-13.239) was associated with worse current cognitive function. Older age (OR: 1.024, 95% CI: 1.003 to 1.046), COVID-19 severity (OR: 2.277, 95% CI: 1.308 to 3.964), mechanical ventilation (OR: 5.388, 95% CI: 3.007 to 9.656), and hypertension (OR: 1.866, 95% CI: 1.376 to 2.531) were associated with an increased risk of longitudinal cognitive decline.Interpretation: SARS-CoV-2 infection is associated with delayed cognitive decline in elderly population. COVID-19 patients with risk factors, including severe disease, older age, mechanical ventilation, and hypertension, should be intensively monitored for delayed cognitive decline. Funding: National Natural Science Foundation of China.Conflict of Interest: We declared no conflict of interests.Ethical Approval: The study protocols were approved by the institutional review boards of the hospitals. Verbal informed consent was obtained from all participants prior to the survey.