Subdomains of Post-COVID-Syndrome (PCS) -- A Population-Based Study

Post-COVID Syndrome (PCS), encompassing the multifaceted sequelae of COVID-19, can be severity-graded using a score comprising 12 different long-term symptom complexes. Acute COVID-19 severity and individual resilience were previously identified as key predictors of this score. This study validated these predictors and examined their relationship to PCS symptom complexes, using an expanded dataset (n=3,372) from the COVIDOM cohort study. Classification and Regression Tree (CART) analysis resolved the detailed relationship between the predictors and the constituting symptom complexes of the PCS score. Among newly recruited COVIDOM participants (n=1,930), the PCS score was again found to be associated with both its putative predictors. Of the score-constituting symptom complexes, neurological symptoms, sleep disturbance, and fatigue were predicted by individual resilience, whereas acute disease severity predicted exercise intolerance, chemosensory deficits, joint or muscle pain, signs of infection, and fatigue. These associations inspired the definition of two novel PCS scores that included the above-mentioned subsets of symptom complexes only. Both novel scores were inversely correlated with quality of life, measured by the EQ-5D-5L index. The newly defined scores may enhance the assessment of PCS severity, both in a research context and to delineate distinct PCS subdomains with different therapeutic and interventional needs in clinical practise.