An estimated 6.2% of individuals with symptomatic SARS-CoV-2 infection experienced at least 1 of 3 long COVID symptom clusters — persistent fatigue with bodily pain or mood swings, cognitive problems, or ongoing respiratory issues — in 2020 and 2021, according to the Global Burden of Disease Long COVID Collaborators modeling study published in JAMA.
Researchers sought to determine the percentage of males and females with a SARS-CoV-2 infection — either 20 years of age or younger or 20 years of age and older — who reported having long COVID symptoms in 2020 and 2021, and to evaluate the severity and anticipated duration of their symptoms. They used data from 54 studies (44 published studies and 10 collaborating cohort studies) and 2 medical record databases for individuals with a symptomatic COVID-19 infection.
The 10 collaborating cohort studies were conducted in Austria, the Faroe Islands, Germany, Iran, Italy, The Netherlands, Russia, Sweden, Switzerland, and the United States. The research was carried out as part of the Global Burden of Diseases, Injuries, and Risk Factors Study. All of the participant data were derived from the 44 published studies (10,501 hospitalized patients and 42,891 nonhospitalized patients), the 10 collaborating cohorts (10,526 hospitalized patients and 1906 nonhospitalized patients), and the 2 US electronic medical databases (250,928 hospitalized patients and 846,046 nonhospitalized patients).
The analysis had 5 components, including the
- proportion of symptomatic survivors with 1 or more of the 3 symptom clusters of long COVID;
- proportion of individuals with long COVID symptom clusters following an acute SARS-CoV-2 infection estimated via a Bayesian meta-regression tool, in which hospitalized and nonhospitalized individuals were considered separately;
- pooling of estimates from the study that provided distributions of symptom cluster overlap, along with severity gradients of cognitive and respiratory issues;
- estimates of daily SARS-CoV-2 infections, hospitalizations, intensive care unit admissions, and deaths due to COVID-19; and
- global estimates of survivors of symptomatic COVID-19 that were multiplied by the proportion of individuals who experienced at least 1 of the 3 long COVID symptom closers 3 months following a SARS-CoV-2 infection.
The estimates, therefore, do not reflect the burden of the full range of Long COVID outcomes.
A total of 1.2 million individuals with symptomatic SARS-CoV-2 infection were included in the analysis. The mean patient age ranged between 4 and 66 years. In the modeled estimates, 6.2% (95% uncertainty interval [UI], 2.4%-13.3%) of individuals with symptomatic SARS-CoV-2 infection reported experiencing 1 or more of the 3 long COVID symptom clusters in 2020 and 2021, including:
- 3.2% (95% UI, 0.6% to 10.0%) for persistent fatigue with bodily pain or mood swings;
- 3.7% (95% UI, 0.9% to 9.6%) for ongoing respiratory problems; and
- 2.2% (95% UI, 0.3% to 7.6%) for cognitive issues.
These are the estimates following adjustments for health status prior to COVID-19, which comprised an estimated 51.0% (95% UI, 16.9% to 92.4%); 60.4% (95% UI, 18.9% to 89.1%); and 35.4% (95% UI, 9.4% to 75.1%), respectively, of long COVID cases.
Long COVID symptom clusters were shown to be more common among women 20 years of age and older compared with men 20 years of age and older following a symptomatic SARS-CoV-2 infection (10.6%; 95% UI, 4.3%-22.2% vs 5.4%; 95% UI, 2.2%-11.7%, respectively). Both sexes who were 20 years of age or younger were estimated to be affected in 2.8% (95% UI, 0.9% to 7.0%) of symptomatic SARS-CoV-2 infections.
The estimated mean duration of long COVID symptom cluster was 9.0 months (95% UI, 7.0-12.0 months) among hospitalized patients vs 4.0 months (95% UI, 3.6-4.6 months) among nonhospitalized individuals. Additionally, in patients with long COVID symptoms 3 months after experiencing a symptomatic SARS-CoV-2 infection, symptoms persisted at 12 months in an estimated 15.1% (95% UI, 10.3%-21.1%) of patients.
The estimated proportion of patients admitted to the ICU (43.1%; 95% UI, 22.6-65.2) or general hospital wards (27.5%; 95% UI, 12.1-47.8) with at least 1 of the 3 long COVID symptom clusters was greater compared with patients who were not hospitalized (5.7%; 95% UI, 1.9-13.1).
In 38.4% of all long COVID cases, 2 or all 3 of the symptom clusters overlapped.
Several limitations of the current study warrant mention. To begin, the 95% UIs regarding the estimates are wide, thus reflecting limited and heterogeneous data. Further, separate algorithms needed to be devised for each of the contributing studies, in an effort to achieve consistency in the case definition of the 3 selected long COVID symptom clusters. Additionally, it was assumed that long COVID follows a similar course in all countries and territories throughout the world.
The researchers concluded that the “The estimates, therefore, do not reflect the burden of the full range of Long COVID outcomes.”
Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.