A multidimensional network of factors associated with long COVID in the French population

Abstract

Background: Various factors associated with long COVID have been evidenced, but the heterogeneity of definitions and epidemiological investigations has often hidden risk pathways relevant for understanding and preventing this condition.

Methods: This nationwide random sampling survey conducted in France after the Omicron waves in autumn 2022 assessed eight sets of factors potentially associated with long COVID in a structured epidemiological investigation based on a conceptual model accounting for the relationships between these sets of factors. A representative sample of 1813 adults of whom 55% were infected with SARS-CoV-2 was assessed for infection dates and context, post-COVID symptoms and these factors. Four definitions of long COVID, including the World Health Organisation's, were used.

Results: Female sex, household size (≥2), low financial security, negative impact of COVID-19 pandemic on occupation and work conditions, number of comorbidities (≥2), presence of respiratory disease, mental and sensory disorders, number of SARS-CoV-2 infections (≥2) and initial symptoms (≥6), perceived high severity of COVID-19 are positively and consistently associated with long COVID. Age ≥ 75 years, retirement, SARS-CoV-2 vaccination (≥2 doses) and good perceived information regarding long Covid are negatively associated with the condition.

Conclusions: The broad spectrum of factors confirmed here strongly suggests that long COVID should be regarded not only as a direct complication of SARS-CoV-2 infection but also as driven by a broader network of contextual, medical, psychological and social factors. These factors should be better considered in strategies aimed at limiting the long COVID burden in the general population.

Fig. 1. Flow chart of the study.

*Sampling ratio 1/2.0. †Sampling ratio 1/5.7 (sampling ratio of 1/7.0 during the first 3 weeks of the survey and 1/5.0 thereafter; the change is due to the higher levels of SARS-CoV-2 infection than initially excepted).

Fig. 2

Conceptual model and sets of risk factors for long COVID. Eight sets of factors for long COVID are distinguished and evaluated in six stages in the statistical analysis (the third, fourth and fifth sets are tested at the same third stage). SEP socioeconomic position, ICU intensive care unit admission.

Fig. 3. Overview of the comparisons performed.

1: Analysis according the paradigm of long COVID as a specific complication of SARS-CoV-2 infection. 2: Analysis according to the paradigm of long COVID as a non-specific condition, potentially arising from causes other than SARS-CoV-2 infection.