Background: The demographic characteristics of people who choose to participate in population-based research studies impacts the generalisability of research findings.
Aim: To examine factors associated with participation in a randomised controlled trial of melanoma prevention in the Australian general population.
Methods: A total of 6,402 Australians aged 18-69 years in the Medicare database were invited by the Department of Human Services on behalf of the University of Sydney to participate in a study examining the impact of personalised melanoma genomic risk information on skin cancer prevention behaviours. We examined the proportion of people who gave consent according to age, sex and the SEIFA Index of Relative Socio-economic Advantage and Disadvantage (a low score indicates a greater relative disadvantage).
Results: A total of 251 (4%) participants gave consent, were eligible and completed baseline measures, but this differed by age and sex groups: men aged 18-44 years: 2%, women aged 18-44 years: 4%, men aged 45-69 years: 5% and women aged 45-69 years: 8%. Higher SEIFA scores were associated with a higher consent rate; people mailed invitations had a mean SEIFA of 1005 (SD 73.5) and those enrolled in the study had a mean of 1024 (SD 70.3); mean difference = 17.6, 95% confidence interval of 8.3-26.9, p = 0.0002). This SEIFA association with participation was consistent across age, sex and state/territory subgroups.
Conclusion: Higher participation in a population-based study involving personalised genomic risk information was associated with female sex, older age-group and higher socioeconomic status.