SynthesisPloS one2024
Biases and limitations in observational studies of Long COVID prevalence and risk factors: A rapid systematic umbrella review.
Synthesis in PloS one, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
13 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Prevalence of cardiovascular symptoms in post-acute COVID-19 syndrome: a meta-analysis.BMC medicine · 2025Pooled it
- Neurological Manifestations of Long COVID: Current Evidence, Emerging Concepts, and Future Perspectives.Journal of clinical medicine · 2026Review
- Persistent Symptoms After SARS-CoV-2 Infection in a Referred Occupational Clinical Registry: Symptom Patterns and Associated Factors.Diseases (Basel, Switzerland) · 2026Article
- Considerations for epidemiological studies investigating emerging post-acute infection syndromes: Long Covid as a case study.EClinicalMedicine · 2026Review
- COVID-19 related brain MRI changes and anticipated long-term dementia risk: A front-door-criterion-inspired approach.Annals of epidemiology · 2026Article
- Sex Differences in Long COVID Prevalence Over One year After the Acute Phase, and Related Risk Factors. The GINA-COVID Cohort Study.International journal of women's health · 2026Article
- Long COVID in adults - a current review of the long-term health effects following SARS-CoV-2 infection.Journal of health monitoring · 2026Article
- Post-COVID-19 condition in individuals infected with SARS-CoV-2 in autumn 2023 in the Netherlands: a prospective cohort study with pre- and post-infection data.The Lancet regional health. Europe · 2025Article
- Post-COVID-19 Condition in Track and Field Master Athletes: Severity, Symptoms, and Associations With Quality of Life and C-Reactive Protein Levels.Scandinavian journal of medicine & science in sports · 2025Article
- Predictive Ability of Previous Pain and Disease Conditions on the Presentation of Post-COVID Pain in a Danish Cohort of Adult COVID-19 Survivors.European journal of pain (London, England) · 2025Article
- Post-COVID-19 condition in prospective inpatient and outpatient cohorts.Scientific reports · 2025Observational
- Article
- Symptom profile, case and symptom clustering, clinical and demographic characteristics of a multicentre cohort of 1297 patients evaluated for Long-COVID.BMC medicine · 2024Article
Corrections and comments
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Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundObservational studies form the foundation of Long COVID knowledge, however combining data from Long COVID observational studies has multiple methodological challenges. This umbrella review synthesizes estimates of Long COVID prevalence and risk factors as well as biases and limitations in the primary and review literatures. METHODS AND
findingsA systematic literature search was conducted using multiple electronic databases (PubMed, EMBASE, LitCOVID) from Jan 1, 2019 until June 9, 2023. Eligible studies were systematic reviews including adult populations assessed for at least one Long COVID symptom four weeks or more after SARS-CoV-2 infection. Overall and subgroup prevalence and risk factors as well as risk of bias (ROB) assessments were extracted and descriptively analyzed. The protocol was registered with PROSPERO (CRD42023434323). Fourteen reviews of 5-196 primary studies were included: 8 reported on Long COVID prevalence, 5 on risk/protective factors, and 1 on both. Prevalence of at least 1 Long COVID symptom ranged from 21% (IQR: 8.9%-35%) to 74.5% (95% CI: 55.6%-78.0%). Risk factor reviews found significant associations between vaccination status, sex, acute COVID-19 severity, and comorbidities. Both prevalence and risk factor reviews frequently identified selection and ascertainment biases. Using the AMSTAR 2 criteria, the quality of included reviews, particularly the prevalence reviews, were concerning for the adequacy of ROB assessments and justifications for conducting meta-analysis.
conclusionA high level of heterogeneity render the interpretation of pooled prevalence estimates of Long COVID challenging, further hampered by the lack of robust critical appraisals in the included reviews. Risk factor reviews were of higher quality overall and suggested consistent associations between Long COVID risk and patient characteristics.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.