Supplementary Material for: Perceived chronic stress prior to SARS-CoV-2 infection predicts ongoing symptomatic COVID-19: a prospective cohort study

Introduction: Understanding chronic stress as a potential risk factor for COVID-19 progression could inform public health measures and personalized preventive interventions. Therefore, we investigated the influence of chronic stress prior to SARS-CoV-2 infection on symptom persistence one month after COVID-19 onset.
Methods: The participants of this prospective cohort study named “StressLoC” were adults with COVID-19 who had tested positive for SARS-CoV-2infection within the last seven days. Pre-existing perceived chronic stress assessed by the Perceived Stress Scale (PSS-10) was the primary predictor. The number of stressful life events and hair cortisol concentration served as additional measures of pre-existing chronic stress. The main outcome was examined using the Long COVID Symptom and Impact Tool. It was defined as the presence of any new and impactful COVID-19-related symptom at month 1 after inclusion. Accordingly, participants were assigned to either the ongoing symptomatic COVID-19 group (OSC-G) or control group (CG).
Results: The study cohort comprised 288 participants (73.3% female), with a median age of 46 years (IQR 35-56). A total of 210 participants (72.9%) were categorized as OSC-G. Multivariate logistic regression showed that allocation to OSC-G was predicted by perceived chronic stress in the month prior to COVID-19 (OR: 1.08, 95% CI: 1.03 to 1.14; p = .002) and the number of pre-existing symptoms (OR: 1.08, 95% CI: 1.03 to 1.13; p = .001). The number of stressful life events and hair cortisol concentration did not predict OSC-G allocation.
Conclusion: Results suggest that higher levels of pre-existing perceived chronic stress increase the odds of developing ongoing symptomatic COVID-19.