Merikanto, IlonaDauvilliers, YvesChung, FrancesWing, Yun Kwokde Gennaro, LuigiHolzinger, BrigitteBjorvatn, BjørnMorin, Charles M.Penzel, ThomasBenedict, ChristianKoscec Bjelajac, AdrijanaChan, Ngan YinEspie, Colin A.Hrubos-Strøm, HaraldInoue, YuichiKorman, MariaLandtblom, Anne MarieLéger, DamienMatsui, KentaroMota-Rolim, SergioNadorff, Michael R.Plazzi, GiuseppeReis, CátiaYordanova, JulianaPartinen, Markku2022-10-192022-10-192023-010962-1105http://hdl.handle.net/10400.14/39145Many people report suffering from post-acute sequelae of COVID-19 or “long-COVID”, but there are still open questions on what actually constitutes long-COVID and how prevalent it is. The current definition of post-acute sequelae of COVID-19 is based on voting using the Delphi-method by the WHO post-COVID-19 working group. It emphasizes long-lasting fatigue, shortness of breath and cognitive dysfunction as the core symptoms of post-acute sequelae of COVID-19. In this international survey study consisting of 13,628 subjects aged 18–99 years from 16 countries of Asia, Europe, North America and South America (May–Dec 2021), we show that post-acute sequelae of COVID-19 symptoms were more prevalent amongst the more severe COVID-19 cases, i.e. those requiring hospitalisation for COVID-19. We also found that long-lasting sleep symptoms are at the core of post-acute sequelae of COVID-19 and associate with the COVID-19 severity when COVID-19 cases are compared with COVID-negative cases. Specifically, fatigue (61.3%), insomnia symptoms (49.6%) and excessive daytime sleepiness (35.8%) were highly prevalent amongst respondents reporting long-lasting symptoms after hospitalisation for COVID-19. Understanding the importance of sleep-related symptoms in post-acute sequelae of COVID-19 has a clinical relevance when diagnosing and treating long-COVID.engCOVID-19Excessive daytime sleepinessFatigueInsomniaPandemicPost-acute sequelae of COVID-19journal article10.1111/jsr.1375485139382422PMC987458436208038000864978900001