The effectiveness of poster and video media education to increase mothers' knowledge of toddlers about diarrhea prevention at the melati integrated health post (posyandu)

Childhood diarrhea remains an important preventable cause of morbidity, and caregiver knowledge is an important component of household prevention. This study examined changes in mothers’ knowledge of diarrhea prevention after health education using poster and educational video media at Melati Posyandu, Binjai, North Sumatra. A true experimental two-group pretest–posttest design was used. Thirty-six mothers of toddlers were recruited by total sampling and randomly assigned to a poster group (n=18) or an educational-video group (n=18). Knowledge was measured using a 20-item Health Belief Model-based questionnaire. Data were assessed using Shapiro–Wilk tests, paired-samples t-tests, and normalized gain analysis. Both interventions produced significant within-group improvements in knowledge (p<0.001). Mean scores increased from 57.89 to 64.06 in the poster group and from 56.33 to 62.11 in the video group. The reported normalized gain was 80.06% for posters and 77.63% for videos. Thus, both media were associated with improved knowledge, while the poster group showed a descriptively higher gain. The findings support the use of accessible visual and audiovisual media in Posyandu-based diarrhea-prevention education, with media selection adapted to local needs and opportunities for repeated exposure.