Extensive European study finds very high rates of long-COVID

In a recent study published by the European Center for Disease Prevention and Control, researchers assessed the prevalence of post-coronavirus disease 2019 (COVID-19) condition symptoms.

To make it easier to document clinical side effects following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the World Health Organization (WHO) developed the International Classification of Disease (ICD) codes in September 2020. The WHO used the Delphi approach to produce a consolidated clinical case definition, using the terminology “post-COVID-19 condition” in response to the wide variety of symptom constellations included in the various definitions for “long COVID.” The post-COVID-19 condition’s management continues to be challenging for healthcare providers, and it may threaten healthcare systems that the pandemic has already overburdened.

Systematic review: Prevalence of post COVID-19 condition symptoms: a systematic review and meta-analysis of cohort study data, stratified by recruitment setting. Image Credit: Donkeyworx / Shutterstock

About the study

In the present study, researchers identified symptoms of post-COVID-19, quantified their prevalence, and ascertained whether COVID-19 disease severity affected symptom prevalence for patient cohorts.

Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and Meta-analyses Of Observational Studies in Epidemiology (MOOSE) protocols were used for conducting the present systematic review. This meta-main analysis estimated the prevalence of post-COVID-19 condition symptoms as a proxy for illness severity, classified according to recruitment setting into community, hospital, and intensive care units (ICU).

Only retrospective and prospective cohort studies performed in Europe, the United Kingdom, the United States, Australia, Canada, and New Zealand were deemed eligible if they satisfied the following conditions: (a) the study assessed patients having a confirmed SARS-CoV-2 diagnosis in one of the community, hospital, or ICU settings, and (b) the study described the post-COVID-19 condition as occurring a minimum of 12 weeks after SARS-CoV-2 infection.

Within Medline (OVID) and EMBASE, peer-reviewed articles published between January 2020 and February 2022 were identified. A thorough search strategy was created using terms related to the post-COVID-19 condition and cohort trial design. In order to find more pertinent studies, the reference lists of all included studies and reviews were also checked.

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The degree of certainty in the evidence obtained for each relevant outcome was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). According to GRADE recommendations, all study outcomes were given an initial score of high certainty before being rated down for flaws like inconsistency, evidence of publication bias, indirectness or inaccuracy of results, or rated up for methodologically robust studies with significant observed effects.


Thorough electronic searches across EMBASE and Medline resulted in 7,125 peer-reviewed studies. Following a full-text evaluation, it was determined that 272 studies met the inclusion criteria and were subsequently further assessed for eligibility. With a sample size ranging between 13 and 57,748 SARS-CoV-2 infected patients within each study, 61 cohort studies contained 74,213 cases of post-COVID-19 conditions that were evaluated a minimum of 12 weeks after SARS-CoV-2 infection. In addition, 58 papers used reverse transcription–polymerase chain reaction (RT-PCR) to diagnose COVID-19, three studies employed clinical diagnosis or serological/antibody assays, and nine studies used clinical and serological methods in addition to RT-PCR.

The prevalence of any symptom associated with the post-COVID-19 condition was 50.6% among community-recruited cohorts, 66.5% among hospital-recruited cohorts, and 73.8% among ICU-recruited cohorts. The most widely documented symptoms from patients enrolled in the community setting, taking into account only prevalence estimates having high or moderate certainty, were general weakness, shortness of breath, fatigue, depression, headache, concentration issues, dizziness, and body aches.

The most common symptoms reported by patients enrolled in the hospital setting, taking into account only prevalence estimates having high or moderate certainty, were cough, constipation, dizziness, depression, diarrhea, fatigue, hair loss, headache, joint pain, nausea, palpitations, rash, shortness of breath, stomach upset, and vomiting. Evidence with a high or moderate degree of certainty supported the prevalence estimates corresponding to five symptoms of post-COVID-19 conditions, namely depression, fatigue, dizziness, shortness of breath, and headache in the community and hospital settings. Each of these symptoms was found to be more common in hospitalized patients than in patients from the community setting.


The study findings identified a broad spectrum of physical and psychological symptoms experienced by SARS-CoV-2-infected people at least 12 weeks after contracting the SARS-CoV-2 virus. Overall, it was estimated that among cohorts recruited in the community, post-COVID-19 condition symptoms were more prevalent in hospital and ICU settings compared to individuals recruited from the community.