Investigating the effect of providing monetary incentives to participants on completion rates of referred co-respondents: An embedded randomized controlled trial

The use of a second informant (co-respondent) is a common method of identifying potential bias in outcome data (e.g., parent-report child outcomes). There is, however, limited evidence regarding methods of increasing response rates from co-respondents. The use of financial incentives is associated with higher levels of engagement and follow-up data collection in online surveys. This study investigated whether financial incentives paid to index participants in an online trial of a parenting-focused intervention, would lead to higher levels of co-respondent data collection.