Factors Associated with Cognitive Performance in Post-COVID Condition: a Multivariate Analysis

Contributing factors on cognitive dysfunction in post-COVID condition (PCC) remain unclear. We aimed to examine the influence of clinical variables (such as disease severity, time since onset, waves, and reinfections), demographic factors (age, years of education, and sex), and comorbidities (fatigue and depression) on cognitive performance.

Two hundred thirty-six patients were evaluated using a comprehensive clinical and neuropsychological protocol. A total of 18 tests from two batteries (standardized and computerized) were administered. One hundred forty-eight controls were also included. Linear models were used to evaluate the effect and interaction of the different variables on cognitive performance.

We found significant main effects of hospitalization, sex, and waves as factors, along with years of education, age, depression, and fatigue as covariates. Hospitalization during the acute stage was significantly associated with almost all attention, memory, and executive function tests. Older hospitalized patients performed better than younger. Sex was only associated with attentional tests. Reinfections and time since the onset showed no significant associations. The interaction between hospitalization and fatigue was different for attention (non-hospitalized showed worse cognitive performance with higher fatigue levels) and episodic memory (hospitalized patients displayed worse performance with higher fatigue levels). The effect of fatigue on cognitive function was different in the first wave compared to the following ones, in which the effect was greater.

Several factors are linked to cognitive performance in PCC, interacting with one another and exhibiting different effects. Recognizing these factors is relevant for future studies evaluating the pathophysiology of cognitive dysfunction in PCC.