Opt-out rates and reasons for non-participation in a single-arm feasibility trial (ENGAGE) of a guided internet-administered CBT-based intervention for parents of children treated for cancer

Data to support a cross-sectional nested survey embdeed with the ENGAGE study, a single-arm feasibility study (ENGAGE) of a guided, internet-administered, CBT-based intervention for parents of children treated for cancer. Primary objectives examined opt-out and consent rates, mode and time point of opt-out, and sociodemographic characteristics of those who opted out versus chose to participate in the ENGAGE study. Secondary objectives examined reasons for non-participation.