A global systematic analysis of the occurrence, severity, and recovery pattern of long COVID in 2020 and 2021

Abstract

ImportanceWhile 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.

The health impact of long COVID during the 2021-2022 Omicron wave in Australia: a quantitative burden of disease study

“…However, a recent study by the IHME quantified long COVID parameters across three separate symptom groups (cognitive difficulty, fatigue, and shortness of breath). 26 In a supplementary analysis (Appendix 7), we calculated long COVID morbidity with the IHME's estimates, and found comparable results.…”

“…Duration was applied differentially by acute COVID-19 severity, based on recent findings by Wulf Hansen et al, who reported a median duration of symptoms for community infections of 4 months, and 8.9 months for previously hospitalised cases. 26 Exceptions to this have been applied to psychological symptoms, for which a shorter duration is estimated, as well as for children (see Table 2). 18,19,27…”

“…Duration was applied differentially by acute COVID-19 severity, based on recent findings by Wulf Hansen et al, who reported a median duration of symptoms for community infections of 4 months, and 8.9 months for previously hospitalised cases. 26 Exceptions to this have been applied to psychological symptoms, for which a shorter duration is estimated, as well as for children (see Table 2). 18,19,27 Uncertainty in base case long COVID estimates was initially estimated by applying a standard deviation of +/-20% to overall long COVID morbidity estimates (this approximated the uncertainty we estimated using a comprehensive bottom-up approach, detailed in Appendix 3).…”

The Use of Palmitoylethanolamide in the Treatment of Long COVID: A Real-Life Retrospective Cohort Study

“…The main symptoms include extreme tiredness, shortness of breath, chest pain or tightness and “brain fog” (that is problems with memory and concentration), as well as difficulty sleeping, heart palpitations, dizziness and joint pain. Persistence of anosmia and dysgeusia [ 9 ] or neuropsychiatric complications are also possible [ 10 , 11 , 12 , 13 ]. Therefore, the increasing importance of long COVID symptoms and burden, led the WHO organization to plan several international meetings with experts reaching a consensus on a definition and reporting details and the subtypes and case definitions of this condition [ 13 ].…”

Post-COVID Phenotypic Manifestations are Associated with New-Onset Psychiatric Disease: Findings from the NIH N3C and RECOVER Studies

“…1 Many patients experience manifestations that persist following acute COVID-19 or with onset after the acute period, affecting various organ systems. [2][3][4][5] These manifestations, when not explained by another cause, are part of the broader syndrome of Post Acute Sequelae of SARS-CoV2 Infection (PASC; colloquially referred to as Long COVID). The rate of newly diagnosed psychiatric disease has been found to be significantly increased in patients following COVID-19 infection.…”