Figure 1.

Participation and non-participation among SCOPI study invitees, Dublin and Sligo, Ireland, 22 June–16 July 2020 (n = 5,199)

Appt: appointment; COVID-19: coronavirus disease; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; SCOPI: The Study to Investigate COVID-19 (coronavirus disease) Infection in People Living in Ireland.

^a The term ‘cocooning’ was used to describe the request by government to individuals at higher risk of consequences from SARS-CoV-2 infection to stay at home most of the time. This included, e.g. older people (˃ 70 years) in the general population, people who had cancers and rare diseases, organ transplantation, chronic lung illnesses, and those who live in long-term care homes, among others.

The response rate for the questionnaire component of the study was calculated as (F + G + H)/(A − B). The response rate for the seroprevalence component of the study was calculated as H/(A − B − F).