Survey participation to the first Wave of a longitudinal study of older people: the case of the Italian InveCe.Ab study

Longitudinal surveys of older people are very powerful research resources to study social inequalities and monitor older people’s health conditions. However, these surveys pose specific methodological challenges. Response at Wave 1 is a very serious issue; when respondents differ from non-respondents on the variables of interest, research findings may not be accurate. There is currently little knowledge on the processes that drive Wave 1 survey participation in longitudinal surveys of older people. Using a rich set of administrative and survey data from an Italian longitudinal study of older people, we explore the determinants of Wave 1 response and investigate the reasons for refusing to participate. Key findings are that (1) individuals whose partners took part in the survey are nearly four times more likely to participate than those whose partners did not, (2) older men and women show different response patterns, with widowers and women from deprived areas being less likely to respond, (3) the main reason for refusing survey participation is lack of interest in the study.