Acute SARS-CoV-2 infection and self-reported post-acute cognitive dysfunctions from the Danish EFTER-COVID survey

Background: The extent and burden of post-acute cognitive dysfunctions following SARS-CoV-2 infection is uncertain. Methods: 25,485 SARS-CoV-2 test-positive and 25,032 test-negative individuals were repeatedly asked to score symptoms of subjective cognitive deficits 2 to 18 months after test using the “Cognitive complaints in bipolar disorder rating assessment” (COBRA) tool. Poisson mixed-effects models were used to estimate Score Ratios (SRs) by comparing scores between test-positive and test-negative individuals. Results: At each follow-up point, test-positive individuals have low but slightly higher mean COBRA scores compared with test-negatives. For the combined 2–18 months period, COBRA scores among test-positive individuals are 11% higher than corresponding scores among test-negatives (SR_2-18mth = 1.11 (95% CI; 1.09–1.13)). Of effect modifiers explored, being hospitalized with a positive SARS-CoV-2 test particularly elevates COBRA scores (SR_2-18mth = 1.38 (95% CI; 1.24–1.54)). Conclusion: In the general population of SARS-CoV-2 infected individuals, self-reported post-acute scores of cognitive dysfunctions are low and only slightly higher than corresponding scores among test-negatives. Higher COBRA scores among hospitalized SARS-CoV-2 test positives corroborate with long-term cognitive impairment being most pronounced among those with severe SARS-CoV-2 infection.