Article Text
Abstract
Background Cognitive symptoms are often reported by those with a history of COVID-19 infection. No comprehensive meta-analysis of neurocognitive outcomes related to COVID-19 exists despite the influx of studies after the COVID-19 pandemic. This study meta-analysed observational research comparing cross-sectional neurocognitive outcomes in adults with COVID-19 (without severe medical/psychiatric comorbidity) to healthy controls (HCs) or norm-referenced data.
Methods Data were extracted from 54 studies published between January 2020 and June 2023. Hedges’ g was used to index effect sizes, which were pooled using random-effects modelling. Moderating variables were investigated using meta-regression and subgroup analyses.
Results Omnibus meta-analysis of 696 effect sizes extracted across 54 studies (COVID-19 n=6676, HC/norm-reference n=12 986; average time since infection=~6 months) yielded a small but significant effect indicating patients with COVID-19 performed slightly worse than HCs on cognitive measures (g=−0.36; 95% CI=−0.45 to –0.28), with high heterogeneity (Q=242.30, p<0.001, τ=0.26). Significant within-domain effects was yielded by cognitive screener (g=−0.55; 95% CI=−0.75 to –0.36), processing speed (g=−0.44; 95% CI=−0.57 to –0.32), global cognition (g=−0.40; 95% CI=−0.71 to –0.09), simple/complex attention (g=−0.38; 95% CI=−0.46 to –0.29), learning/memory (g=−0.34; 95% CI=−0.46 to –0.22), language (g=−0.34; 95% CI=−0.45 to –0.24) and executive function (g=−0.32; 95% CI=−0.43 to –0.21); but not motor (g=−0.40; 95% CI=−0.89 to 0.10), visuospatial/construction (g=−0.09; 95% CI=−0.23 to 0.05) and orientation (g=−0.02; 95% CI=−0.17 to 0.14). COVID-19 samples with elevated depression, anxiety, fatigue and disease severity yielded larger effects.
Conclusion Mild cognitive deficits are associated with COVID-19 infection, especially as detected by cognitive screeners and processing speed tasks. We failed to observe clinically meaningful cognitive impairments (as measured by standard neuropsychological instruments) in people with COVID-19 without severe medical or psychiatric comorbidities.
Data availability statement
Data are available on reasonable request. Data are available on reasonable request to the corresponding author.
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Data availability statement
Data are available on reasonable request. Data are available on reasonable request to the corresponding author.
Footnotes
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Contributors Concept and design: SABK, DSA, SLA, JEC and BDH. Acquisition, analysis or interpretation of data: SABK, DSA, SLA.Drafting of the manuscript: SABK, DSA, SLA, JEC. Critical revision of the manuscript for important intellectual content: All authors. Statistical analyses: SLA, TO and NCB. Obtaining funding: N/A. Administrative, technical or material support: TO, NCB and BDH. Supervision: SLA, JEC, NCB, VADB, RMR, WPM and BDH. SLA is responsible for the overall content as guarantor.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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