Online Screening to Detect Postacute/Long-COVID Syndrome

Abstract: In this study, we developed and tested a low-threshold online screening tool for postacute/long-COVID syndrome (PACS) to identify individuals who need further clinical assessment. Screening criteria stem from existing literature and diagnostic guidelines. A total of N = 1,366 participants completed the screening tool, n = 784 of whom screened positive for PACS. Of these, n = 63 participants, selected based on feasibility and available clinical resources, underwent comprehensive, 3-day clinical diagnostics (including blood tests). Based on these assessments, clinical practitioners confirmed that n = 60 participants were PACS-positive (95.2 % confirmed cases). Using repeated-measures ANOVA and MANOVA, we assessed differences in symptom severity over time between positive and negative cases. Symptom severity decreased over time ( F‍[2.166] = 18.68, p < .001), and 11 out of 14 symptoms were more severe in those who had screened positive, but we found no significant interaction between time and screening results. These results suggest that the online screening tool effectively diagnoses potential PACS cases and enables a timely prioritization for clinical evaluation. This approach offers an efficient and scalable method for prioritization in primary care, reducing healthcare systems’ burden while ensuring that patients with more severe symptoms receive timely medical attention.