Cognition, function, and mood post-COVID-19: Comparative analysis using the health and retirement study

Millions of Americans endure post-COVID conditions (PCC), yet research often lacks pre-illness measurements, relying primarily on follow-up assessments for analysis. The study aims to examine the prevalence of PCC, including cognitive impairment, functional limitation, and depressive symptoms, along with relevant risk factors, while controlling for individuals' pre-illness status measured in 2018. A cross-sectional retrospective study utilized the 2018 and 2020 Health and Retirement Study surveys. Sample included individuals with COVID-19 (n = 409; average age 64) and individuals without COVID-19 (n = 8689; average age 59). COVID-19 positive: Individuals with positive tests, physician diagnoses, emergency room visits, or hospitalizations for COVID-19 between 2019-2020. Cognition was assessed using immediate and delayed word-recall tests, serial seven subtractions, and backward counting. Functional status was measured using limitations in activities of daily living (ADLs) and instrumental ADLs. Depressive symptoms were measured using the modified Center for Epidemiology Studies Depression scale. Participants' perception of experiencing PCC was collected. Logistic regression and propensity score matching were employed for these analyses. Among 409 COVID-19-positive respondents (14% hospitalized), 24% exhibited new impairments after COVID-19 infection. Noteworthy increases in functional limitation (OR [95% CI]: 2.18 [0.95, 0.97], p < 0.001) and a marginal rise in cognitive impairment (1.79 [0.99, 3.32], p = 0.053) following COVID-19 infection were observed in comparison to their pre-COVID-19 baseline. Compared to 8689 non-COVID-19 cases, the 409 COVID-19 positives showed increased functional decline (1.78 [1.26, 2.51], p = 0.001) and depressive symptoms (1.41 [1.04, 1.91], p = 0.03). Factors associated with PCC included pre-existing impairments, lower education, female gender, prior hospitalization, higher comorbidity, lower wealth, and mild COVID-19. A notable number of respondents, especially older individuals with fewer pre-existing health conditions, experienced PCC without awareness. Compared to an individual's pre-illness baseline and uninfected individuals, being positive for COVID-19 raised the risk of functional limitation, depressive symptoms, and cognitive impairment. Additionally, addressing PCC through both subjective and objective approaches is essential to alleviate individual and societal burdens.