Background

Since the start of the COVID-19 pandemic, a significant and growing number of people infected with the SARS-CoV-2 virus have reported suffering from prolonged or recurring symptoms that impair their daily functioning for several weeks or even months after infection.

In 2021, the World Health Organization (WHO) classified this condition as “post-COVID-19 condition” (also known as long COVID) and, in October 2021, provided a definition for it.

An initial study on the prevalence and impact of post-COVID-19 conditions was conducted in early 2022 among the population aged 18 and older residing in metropolitan France, using a sample selected from a panel of volunteers via the quota method. This study showed that 30% of respondents infected with SARS-CoV-2 had post-COVID-19 syndrome according to the WHO definition. This corresponded to a prevalence of 4% in the general population.

• Learn more: Update on "Post-COVID-19 condition (also known as Long COVID) in France. Update as of July 21, 2022."

The methodological limitations of this initial study mean that these results need to be confirmed and refined using a random sample covering the entire French population. Furthermore, the succession of new epidemic waves linked to the active circulation of new sublineages of the Omicron variant since early spring 2022 requires that the estimate be updated. Finally, it is necessary to deepen our understanding of the impact of this condition on healthcare utilization, quality of life, and mental health in the general population, in order to ensure the implementation of appropriate public policy.

Thus, despite the recognized impact of post-COVID-19 conditions on the population, knowledge about them remains limited and requires further documentation through additional research.

Objectives

Primary Objective

• To estimate the prevalence and number of people with post-COVID-19 conditions in the general adult population in metropolitan France in the fall of 2022.

Secondary objectives

• To assess healthcare utilization, quality of life, and mental health among people with post-COVID-19 syndrome

• Assess the specific nature of symptoms associated with post-COVID-19 syndrome

• To explore the public’s knowledge and perceptions regarding post-COVID-19 conditions

• To explore the determinants and estimate the duration of post-COVID-19 conditions

• Assess vulnerability factors and their link to post-COVID-19 conditions, such as social isolation, workplace exposure, and risky behaviors (e.g., alcohol and tobacco use)

• Study and characterize the most vulnerable populations (isolated older adults, people living with chronic diseases, lower socioeconomic status groups; immigrants) in terms of post-COVID-19 symptoms

• Explore the link between post-COVID-19 conditions and the presence of chronic diseases

Survey Launch Schedule

The pilot study took place between August 3 and 12, 2022, with 100 participants. The study will be rolled out in mainland France between September and November 2022.

Study Population

This study focuses on the French adult population residing in mainland France aged between 18 and 75. Participants must have a landline or mobile phone, be available during the study period, and be able to complete the questionnaire in French.

Study Procedure

10,000 participants will be surveyed by IPSOS. The sample of the target population will be selected through random sampling from an updated database of telephone numbers (landlines and cell phones) to cover the entire French population residing in mainland France and owning a telephone. Only one person may be surveyed per telephone number.

Data collection will take place in two stages:

1. Step 1: Collection of sociodemographic information, basic information on general health status and healthcare utilization, any history of SARS-CoV-2 infection, hospitalization, and admission to an intensive care unit, information on workplace exposure, and finally on the symptoms of any potential post-COVID-19 condition via telephone (duration ~10 minutes).

2. Step 2: Collection of more detailed information regarding health status, including pre-existing chronic conditions, healthcare utilization, mental health, quality of life and social support, vaccination, health-related behaviors (e.g., alcohol and tobacco use, and physical activity), the impact of the crisis on income and professional life, use of sick leave, and finally, knowledge and perceptions regarding post-COVID-19 conditions via a self-administered web questionnaire. A telephone interview may be offered if the web-based option is declined (duration ~30 minutes).

Preliminary results of the study

• 4% of participants met the criteria for a post-COVID-19 condition (corresponding to 2.06 million people), and 1.2% reported a strong or very strong impact on their daily activities.

• 7.1% of participants reported having had long COVID when asked (reported long COVID).

• Among the 48% of people who had been infected with SARS-CoV-2 more than three months prior, 8% met the criteria for a post-COVID-19 condition.

• Prevalence was higher among women (10.2%), job seekers (14.9%), and individuals who had been hospitalized for COVID-19 (18.6%).

• 21.3% of people reporting a post-COVID-19 condition were infected during the Delta variant wave, and 53.2% during the Omicron variant waves.

Learn more: Survey "Long COVID - Post-COVID-19 Condition, Metropolitan France," September–November 2022, preliminary results

Regulatory Framework and Data Rights

The study has received approval from the Ethics and Professional Conduct Committee (CED) of Santé publique France.

Participation in this survey is voluntary. In accordance with the French Data Protection Act, participants have the right to access, correct, transfer, delete, or restrict the processing of their data. Additionally, they may object to the processing of their data for reasons related to their specific situation and have the right to withdraw their consent at any time.

• More information regarding data processing and your rights