2604.01671 COVID-LONG v1: Pre-Validation Framework for Long-COVID Probability at 6 Months by Acute-Phase Features
COVID-LONG v1: We present a pre-validation composite scoring framework for symptom persistence meeting WHO PCC criteria at 6 months post-index in adults with a confirmed SARS-CoV-2 infection who have completed the acute phase (>=28 days post-symptom onset). Published literature reports long-COVID prevalence 10-30% at 6 months depending on population and definition [Davis 2021; Global Burden Collaborators 2022; NICE 2022], with effect sizes for individual modifiers reported inconsistently across study designs and grading conventions.