Effectiveness of Genetic Counseling Modalities on Knowledge, Attitudes, and Premarital Screening Intentions for Thalassemia Prevention: A Multi-Site Three-Arm Randomized Controlled Trial.

Thalassemia prevention relies on effective premarital screening. However, participation remains suboptimal because of multiple individual, sociocultural, and structural barriers, including limited knowledge, stigma, cultural and religious beliefs, healthcare accessibility, and socioeconomic constraints. This multi-site three-arm randomized controlled trial evaluated the effectiveness of digital leaflet-based, educational video-based, and face-to-face genetic counseling on knowledge, attitudes, and screening intentions among prospective couples in Ciamis District, Indonesia. A total of 177 prospective couples were randomized (digital leaflet = 59, video = 59, face-to-face = 59). After follow-up, 41, 53, and 59 participants, respectively, completed the post-intervention assessment and were included in the final analysis. Outcomes were measured at baseline and post-intervention using validated questionnaires and analyzed using Wilcoxon signed-rank tests and repeated-measures analysis of variance. Digital leaflet-based counseling significantly improved knowledge and screening intention (p < 0.001), while educational video-based counseling significantly improved knowledge, attitudes, and intention (p < 0.05). Face-to-face counseling showed no statistically significant changes across outcomes. Between-group analyses revealed significant differences in knowledge (η2 = 0.059, p < 0.001), attitudes (η2 = 0.080, p < 0.001), and intentions (η2 = 0.084, p < 0.001), with digital interventions outperforming face-to-face counseling. These findings suggest that digital genetic counseling modalities were associated with greater improvements in knowledge, attitudes, and premarital screening intentions than face-to-face counseling in this study setting.