Pairwise Comparisons of COVID-19 Infection and Smoking Behaviors on Subjective Cognitive Decline.

INTRODUCTION

Subjective cognitive decline represents a critical intervention point for dementia. Independent associations have been observed between smoking and subjective cognitive decline and COVID-19 infection and subjective cognitive decline, but the interplay of these factors is unknown. This study examined whether the association between COVID-19 infection history and subjective cognitive decline differed by smoking behaviors.

METHODS

This cross-sectional study used 2023 Behavioral Risk Factor Surveillance System data from 35 states and Puerto Rico, which included an optional module on cognitive decline. Data were analyzed in 2024. The primary dependent variable was subjective cognitive decline. Independent variables included COVID-19 infection, cigarette smoking/E-cigarette use (current, former, never), and confounding factors. Multivariable log-binomial regression models with interaction terms for the combination of COVID-19 infection history and smoking status were used to estimate adjusted prevalence ratios and 95% CIs for subjective cognitive decline.

RESULTS

The study population included 146,416 adults aged ≥45 years. Participants who experienced COVID-19 were more likely to report subjective cognitive decline regardless of cigarette smoking (adjusted prevalence ratio=1.21; 95% CI=1.14, 1.28) or E-cigarette use (adjusted prevalence ratio=1.21; 95% CI=1.12, 1.31) than those with no COVID-19 infection history. Participants reporting current cigarette smoking and COVID-19 infection history had a significantly higher prevalence of subjective cognitive decline concerns and were more likely to give up day-to-day chores than those who currently smoked with no COVID-19 infection history.

CONCLUSIONS

Individuals with COVID-19 infection history had a higher prevalence of subjective cognitive decline than individuals with no COVID-19 infection history regardless of cigarette/E-cigarette use. Smoking cessation and cognitive training may be dually integrated into post-COVID-19 care.