Prevalence of long COVID in the general adult population according to different definitions and sociodemographic and infection characteristics. A nationwide random sampling survey in France in autumn 2022

Objectives Long COVID is recognized since early 2020, but its definition is not unanimous, which complicates epidemiological assessments. This study estimated the prevalence of long COVID based on several definitions and severity thresholds in the adult population in mainland France and examined variations according to sociodemographic and infection characteristics. Methods A cross-sectional survey using random sampling was conducted in August-November 2022. Participants declaring SARS-CoV-2 infection were assessed for infection dates and context, post-COVID symptoms (from a list of 31, with onset time, daily functioning impact, alternative diagnosis) and perceived long COVID. Long COVID prevalence was estimated according to the World Health Organisation (WHO), National Institute for Health and Care Excellence (NICE), United States National Centre for Health Statistics (US-NCHS) and United Kingdom Office for National Statistics (UK-ONS) definitions. Results Of 10,615 participants, 5,781 (54.5%) reported SARS-CoV-2 infection, with 123 to 759 (1.2% to 13.4%) having long COVID depending on the definition. Prevalence of WHO post-COVID condition (PCC) was 4.0% (95%CI:3.6-4.5) in the overall population and 8.0% (95%CI:7.0-8.9) among infected individuals. Among the latter, prevalence varied from 5.3% (men) to 14.9% (unemployed) and 18.6% (history of hospitalization for COVID-19). WHO-PCC overlapped poorly with other definitions (kappa ranging 0.18-0.59) and perceived long COVID (reported in only 43% of WHO-PCC). Conclusions Regardless of its definition, long COVID remains a significant burden in the French adult population that deserves surveillance, notably for forms that strongly impact daily activities. More standardised definitions will improve integrated surveillance of, and better research on, long COVID.