A global systematic analysis of the occurrence, severity, and recovery pattern of long COVID in 2020 and 2021
Authors: Wulf Hanson Sarah , Abbafati Cristiana , Aerts Joachim G , Al-Aly Ziyad , Ashbaugh Charlie , Ballouz Tala , Blyuss Oleg , Bobkova Polina , Bonsel Gouke , Borzakova Svetlana , Buonsenso Danilo , Butnaru Denis , Carter Austin , Chu Helen , De Rose Cristina , Diab Mohamed Mustafa , Ekbom Emil , El Tantawi Maha , Fomin Victor , Frithiof Robert , Gamirova Aysylu , Glybochko Petr V , Haagsma Juanita A. , Javanmard Shaghayegh Haghjooy , Hamilton Erin B , Harris Gabrielle , Heijenbrok-Kal Majanka H , Helbok Raimund , Hellemons Merel E , Hillus David , Huijts Susanne M , Hultström Michael , Jassat Waasila , Kurth Florian , Larsson Ing-Marie , Lipcsey Miklós , Liu Chelsea , Loflin Callan D , Malinovschi Andrei , Mao Wenhui , Mazankova Lyudmila , McCulloch Denise , Menges Dominik , Mohammadifard Noushin , Munblit Daniel , Nekliudov Nikita A , Ogbuoji Osondu , Osmanov Ismail M , Peñalvo José L. , Petersen Maria Skaalum , Puhan Milo A , Rahman Mujibur , Rass Verena , Reinig Nickolas , Ribbers Gerard M , Ricchiuto Antonia , Rubertsson Sten , Samitova Elmira , Sarrafzadegan Nizal , Shikhaleva Anastasia , Simpson Kyle E , Sinatti Dario , Soriano Joan B , Spiridonova Ekaterina , Steinbeis Fridolin , Svistunov Andrey A , Valentini Piero , van de Water Brittney J , van den Berg-Emons Rita , Wallin Ewa , Witzenrath Martin , Wu Yifan , Xu Hanzhang , Zoller Thomas , Adolph Christopher , Albright James , Amlag Joanne O , Aravkin Aleksandr Y , Bang-Jensen Bree L , Bisignano Catherine , Castellano Rachel , Castro Emma , Chakrabarti Suman , Collins James K , Dai Xiaochen , Daoud Farah , Dapper Carolyn , Deen Amanda , Duncan Bruce B , Erickson Megan , Ewald Samuel B , Ferrari Alize J , Flaxman Abraham D. , Fullman Nancy , Gamkrelidze Amiran , Giles John R , Guo Gaorui , Hay Simon I , He Jiawei , Helak Monika , Hulland Erin N , Kereselidze Maia , Krohn Kris J , Lazzar-Atwood Alice , Lindstrom Akiaja , Lozano Rafael , Magistro Beatrice , Malta Deborah Carvalho , Månsson Johan , Mantilla Herrera Ana M , Mokdad Ali H , Monasta Lorenzo , Nomura Shuhei , Pasovic Maja , Pigott David M , Reiner Robert C , Reinke Grace , Ribeiro Antonio Luiz P , Santomauro Damian Francesco , Sholokhov Aleksei , Spurlock Emma Elizabeth , Walcott Rebecca , Walker Ally , Wiysonge Charles Shey , Zheng Peng , Bettger Janet Prvu , Murray Christopher JL , Vos Theo 
Published: May 2022

AbstractImportanceWhile much of the attention on the COVID-19 pandemic was directed at the daily counts of cases and those with serious disease overwhelming health services, increasingly, reports have appeared of people who experience debilitating symptoms after the initial infection. This is popularly known as long COVID.ObjectiveTo estimate by country and territory of the number of patients affected by long COVID in 2020 and 2021, the severity of their symptoms and expected pattern of recoveryDesignWe jointly analyzed ten ongoing cohort studies in ten countries for the occurrence of three major symptom clusters of long COVID among representative COVID cases. The defining symptoms of the three clusters (fatigue, cognitive problems, and shortness of breath) are explicitly mentioned in the WHO clinical case definition. For incidence of long COVID, we adopted the minimum duration after infection of three months from the WHO case definition. We pooled data from the contributing studies, two large medical record databases in the United States, and findings from 44 published studies using a Bayesian meta-regression tool. We separately estimated occurrence and pattern of recovery in patients with milder acute infections and those hospitalized. We estimated the incidence and prevalence of long COVID globally and by country in 2020 and 2021 as well as the severity-weighted prevalence using disability weights from the Global Burden of Disease study.ResultsAnalyses are based on detailed information for 1906 community infections and 10526 hospitalized patients from the ten collaborating cohorts, three of which included children. We added published data on 37262 community infections and 9540 hospitalized patients as well as ICD-coded medical record data concerning 1.3 million infections. Globally, in 2020 and 2021, 144.7 million (95% uncertainty interval [UI] 54.8–312.9) people suffered from any of the three symptom clusters of long COVID. This corresponds to 3.69% (1.38–7.96) of all infections. The fatigue, respiratory, and cognitive clusters occurred in 51.0% (16.9–92.4), 60.4% (18.9–89.1), and 35.4% (9.4–75.1) of long COVID cases, respectively. Those with milder acute COVID-19 cases had a quicker estimated recovery (median duration 3.99 months [IQR 3.84–4.20]) than those admitted for the acute infection (median duration 8.84 months [IQR 8.10–9.78]). At twelve months, 15.1% (10.3–21.1) continued to experience long COVID symptoms.Conclusions and relevanceThe occurrence of debilitating ongoing symptoms of COVID-19 is common. Knowing how many people are affected, and for how long, is important to plan for rehabilitative services and support to return to social activities, places of learning, and the workplace when symptoms start to wane.Key PointsQuestionWhat are the extent and nature of the most common long COVID symptoms by country in 2020 and 2021?FindingsGlobally, 144.7 million people experienced one or more of three symptom clusters (fatigue; cognitive problems; and ongoing respiratory problems) of long COVID three months after infection, in 2020 and 2021. Most cases arose from milder infections. At 12 months after infection, 15.1% of these cases had not yet recovered.MeaningThe substantial number of people with long COVID are in need of rehabilitative care and support to transition back into the workplace or education when symptoms start to wane.