The COVID-19 pandemic led the government to implement an initial lockdown in France between mid-March 2020 and mid-May 2020, accompanied by various restrictive measures, particularly regarding economic activity. The Coset cohort follow-up survey was designed to study the consequences of the lockdown period and associated measures on the health and employment status of the populations tracked in the Coset-MSA and Coset-Indépendants cohorts. This specifically included farmers and other self-employed individuals in the agricultural sector, employees covered by the agricultural social security system, artisans, merchants, professionals, and their assisting spouses. A total of 27,044 and 20,368 people, respectively, were invited to participate in the follow-up survey. Data collection took place from May 28 to August 9, 2020, via an online self-administered questionnaire. A total of 9,174 and 6,641 individuals, respectively, had valid Coset-MSA and Coset-Indépendants questionnaires for the Coset-Covid survey, representing response rates of 33.9% and 32.6%. The implementation of multiple follow-ups and a dual contact method (email and mail) significantly increased the participation rate without compromising the quality of the responses. This also helped boost participation among groups that tend to be less responsive. Analysis of participation in the Coset-Covid survey led to recommendations for future Coset surveys.