Long COVID

Please note that there are different definitions and guidelines available to describe long COVID. Based on the definition used, the results may be different.
The COVIMPACT study in Sciensano was developed based on the definition of the National Institute of Health and Care Excellence (NICE): "symptoms persist or develop for more than 3 months after a COVID-19 infection and cannot be explained by another diagnosis” [1].

1. Key messages

2. The proportion of long COVID

In the COVIMPACT study, the overall occurrence of long COVID was 47% three months after a SARS-CoV-2 infection, and 32% after 6 months. These numbers are in line with the international literature, which reports a prevalence of 47% and 30% for long COVID at 3 and 6 months [3].

All age groups are affected by long COVID

Although the proportion of long COVID differs slightly according to age, it is not a significant risk factor. Among participants with an age between 18 and 25 years, 47% reported persistent symptoms 3 months after a SARS-Cov-2 infection. This is similar to participants aged between 26 and 45 years where 51% reported persistent symptoms, but higher compared to the other age categories 46-65 years (42%) and 66+ (36%). At 6 months, the prevalence of long COVID has decreased among all age categories to 27%, 26%, 37%, and 21% respectively [3].

Women are more likely to report long COVID

In the COVIMPACT study, 37% of the participants were men and 63% of them were women. The proportion of long COVID at 3 months is higher amongst women (56%) in comparison to men (42%). After 6 months, the proportion decreased in women to 40% and men to 27%. Women are 1.4 times more likely to have long COVID than men at 3 and 6 months.

Participants with lower socioeconomic status are more vulnerable to long-COVID symptoms

Among participants with a lower educational status, 56% reported persistent symptoms 3 months after infection, which is slightly higher compared to patients with a higher educational level (47%). After 6 months, these proportions decrease to respectively 41% and 32%.

The most prevalent symptoms of long COVID are fatigue and exhaustion

The most prevalent symptoms reported by participants with long COVID at 3 and 6 months post-infection are fatigue and exhaustion (49% and 50%), headache (27% and 32%), memory problems (26% and 32%), respiratory problems (21% and 27%), sleeping problems (19% and 22%), loss of smell (20% and 17%) and taste (14% and 13%).

Patients with long COVID report a reduced quality of life

The health-related quality of life has been assessed with the EQ-5D questionnaire, which contains questions on mobility, autonomy, daily activities, pain/discomfort, and anxiety/depression. After 3 months, 18% of participants with long COVID reported mobility problems, 4% autonomy problems, 30% had problems with daily activities, 48% had pain and 40% of them reported anxiety and depression. After 6 months, these proportions were respectively 21% (mobility), 5% (autonomy), 33% (daily activities), 56% (pain), and 49% (anxiety and depression).

The mean score of health-related quality of life was assessed among COVIMPACT participants before their SARS-CoV-2 infection, at the time of infection, and after 3 and 6 months. Before infection, the average quality of life score was 92.6/100 and it significantly decreased at the time of infection to 81.7/100. For the scores 3 and 6 months after infection, a comparison was made between people who recovered from their infection and those who had long COVID. People who recovered from the infection had a higher quality of life score 3 and 6 months after infection (95.7/100 and 95.8/100) than people with long COVID (86/100 and 83.6/100).

3. Read more

View the metadata for this indicator

Context

In Belgium and worldwide, at the beginning of the COVID-19 pandemic, the focus was on managing the acute phase of the disease. However, some people continue to experience symptoms beyond the acute phase of infection [4] [5]. This phenomenon is referred to as "long COVID" or "Post COVID-19 condition" [6].

There is currently no consensus on the definition of long COVID. Still, many studies apply the definition proposed by the National Institute of Health and Care Excellence: "symptoms persist or develop for more than 3 months after a COVID-19 infection and cannot be explained by another diagnosis [1].

In the COVIMPACT study, the two definitions used to describe long COVID 3 and 6 months after acute infection are (1) having at least one symptom related to the SARS-CoV-2 infection three months after it, (2) still have at least one persistent symptom related to the SARS-CoV-2 infection six months after it. The objective of the COVIMPACT project is to constitute a cohort of people who test positive for COVID-19 in order to:

• study the long-term evolution of a SARS-CoV-2 infection on physical, mental, and social health
• identify the groups at risk and the factors associated with a favorable/unfavorable evolution

COVIMPACT is a prospective online observational cohort study. The target group is people who have had a COVID-19 infection confirmed by a laboratory test. When a COVID-19 test is positive, the lab sends the information to a central database that is used by call centers to contact COVID-19 cases and trace their contacts. At the end of the call, the call center agents inform people aged 18 and over about our online survey and ask if they agree to receive a link by SMS for more information on the study, and potentially participate in the study and complete the first questionnaire. Follow-up questionnaires are sent by Sciensano every 3 months until the end of the study in April 2023. Depending on when participants entered the study, the follow-up varies from 3 months to 2 years. Between 29 April 2021 and 1 May 2022, 2092 people completed the first questionnaire and the two follow-up questionnaires (3 and 6 months after infection). Full details on the sample and design are described in the latest COVIMPACT study report. The following topics were assessed in the study: COVID-19, quality of life, breathing difficulties, fatigue, functional limitations, mental health, physical activity, employment, and economic status.

All these results can be found on the COVIMPACT website.

Definitions

SARS-Cov-2 infection

"A confirmed case is defined as a person who has a confirmed diagnosis by molecular or antigenic test of COVID-19 "

Long COVID

The COVIMPACT study in Sciensano was developed based on the definition of the National Institute of Health and Care Excellence (NICE): "symptoms persist or develop for more than 3 months after a COVID-19 infection and cannot be explained by another diagnosis”

References

1. National Institute for Health and Care Excellence,(NICE). (2020). COVID-19 rapid guideline: Managing COVID-19. NICE. https://www.nice.org.uk/guidance/ng191
2. Sciensano.(2020). COVID-19—Définition de cas et testing | Coronavirus Covid-19. https://covid-19.sciensano.be/fr/covid-19-definition-de-cas-et-testing
3. Smith P, Charafeddine R, Drieskens S, De Pauw R, De Ridder K, Demarest S, Van Cauteren D. Etude COVIMPACT : Infection COVID-19 et ses implications physiques, mentales et sociales à long terme – Résultats du suivi à 3 et 6 mois suivant l’infection. Bruxelles, Belgique. Juin 2022. Numéro de dépôt : D/2022.14.440/36 DOI : /10.25608/gyzc-w673
4. Amdal, C. D., Pe, M., Falk, R. S., Piccinin, C., Bottomley, A., Arraras, J. I., Darlington, A. S., Hofsø, K., Holzner, B., Jørgensen, N. M. H., Kulis, D., Rimehaug, S. A., Singer, S., Taylor, K., Wheelwright, S., & Bjordal, K. (2021). Health-related quality of life issues, including symptoms, in patients with active COVID-19 or post COVID-19; a systematic literature review. Quality of Life Research. https://doi.org/10.1007/s11136-021-02908-z
5. Taquet, M., Dercon, Q., Luciano, S., Geddes, J. R., Husain, M., & Harrison, P. J. (2021). Incidence, co-occurrence, and evolution of long-COVID features : A 6-month retrospective cohort study of 273,618 survivors of COVID-19. PLOS Medicine, 18(9), e1003773. https://doi.org/10.1371/journal.pmed.100377
6. World Health Organization, WHO. (2021). A clinical case definition of post-COVID condition by a Delphi consensus. https://apps.who.int/iris/handle/10665/345824