Recruitment and Consent in an observational study

Abstract

OBJECTIVE: The study sought to explore the consent rate and associated potential bias across a cohort in a large longitudinal population based study. RESEARCH DESIGN: Data were taken from a study designed to examine the effects of the reintroduction of community water fluoridation on children's oral health over a five-year period. Children were recruited from a fluoridated and non-fluoridated area in Cumbria, referred to as Group 1 and Group 2. RESULTS: Data were available for 3138 individuals. The consent rate was 12.91 percentage points lower in Group 2 than Group 1 (95% CI -16.27 to -9.56, p⟨0.001). The population in Group 2 was more deprived (higher Index of Multiple Deprivation (IMD)) t..