Ollila HM, Fonseca-Rodríguez O, Caspersen IH, et al. How do clinicians use post-COVID syndrome diagnosis? Analysis of clinical features in a Swedish COVID-19 cohort with 18 months’ follow-up: a national observational cohort and matched cohort study. BMJ public health. 2024;2(1):e000336. doi:10.1136/bmjph-2023-000336