Incidence and risk factors of cognitive impairment in COVID-19 survivors within the first six months and its association with functional outcome

Abstract

Background & Objective: There is growing evidence of cognitive decline post-COVID-19, even in mild infection. We aim to evaluate the incidence of cognitive impairment, domains affected, its risk factors and the effect on function during the subacute period when rehabilitation is crucial.

Methods: In this study, the incidence of impaired cognition was assessed in patients at 3 and 6 months post-COVID-19 infection between August 2021 and July 2022 at University Malaya Medical Center, with Montreal Cognitive Assessment (MoCA). The most common cognitive domains affected were identified with descriptive analysis. Associated sociodemographic and clinical factors were analyzed with simple and multiple logistic regression models. The post-COVID-19 Functional Scale (PCFS) was used to assess functional status. The correlation between cognition (MoCA score) and functional status (PCFS scale) was performed using Spearman correlation test.

Results: We recruited 100 patients and found that 44% had impaired cognition at three months and 43% at six months. Patients with secondary education level (p =0.001, OR 13.541), oxygen therapy (p=0.039, OR 7.811), and obesity (p=0.029, OR 4.764) were associated with a higher risk of impaired cognition. The most affected MoCA domains were language, executive function, attention and memory. Lower MoCA score was correlated with higher PCFS grade (lower functional status) (p <0.001, ρ -0.729).

Conclusion: Post-COVID-19 cognitive impairments were common up to 6 months of illness and affect function. Clinicians are advised to perform cognitive screening especially in higher risk patients and provide necessary interventions.