Influence of Digital Competence on Participation and Retention of Patients with Advanced Cancer and Their Family Caregivers in a Randomized Controlled Trial with an e-Health Component: Findings from the DIAdIC Trial

<b>Background:</b> e-Health programs to empower patients with advanced cancer and their family caregivers can improve their quality of life. Successful engagement with e-Health programs requires digital competence. People with lower digital competence might be less likely to participate and complete e-Health trials, affecting trial validity. The objective of this work was to explore how digital competences differ between individuals according to sociodemographic characteristics and how it influences participation and retention in a trial with an e-Health component. <b>Methods:</b> We analyzed data collected as part of the Dyadic Psychoeducational Interventions for patients with advanced cancer and their Informal Caregivers DIAdIC (DIAdIC) trial, in which a psychoeducational web and face-to-face program for patients with advanced cancer and their family caregivers were developed and tested. Recruitment log files were quantitatively assessed for nonparticipation reasons. Descriptive statistics outlined sociodemographic factors and digital competence. Multivariable linear regressions assessed digital competence. We reported unstandardized coefficients, 95% confidence intervals, and <i>p</i>-values. Logistic regressions examined retention rates. We reported odds ratios and 95% confidence intervals. <b>Results:</b> Among those refusing participation in the trial (<i>N</i> = 1752), 2.1% (<i>n</i> = 37) cited information and communication technology (ICT)-related factors. Enrolled patients reported lower digital competence than family caregivers (mean 3.07, SD 0.94 vs. 3.17, SD 0.090; <i>p</i> = 0.046). While digital competence varied by sociodemographic characteristics of patients and their family caregivers, digital competence did not significantly predict dropout. <b>Conclusion:</b> ICT-related factors were rarely mentioned as a reason for nonparticipation. Digital competence is associated with sex, age, trial location, educational attainment, and perception of income. e-Health-related factors or digital competence are no reasons for nonparticipation in studies with an e-Health component.