<![CDATA[Menarche is a significant milestone in the maturation of adolescent girls and requires adequate physical and psychological preparedness. However, many eleentary school girls experience menarche without sufficient knowledge and readiness. The Health Report Card, known as Rapor Kesehatanku, is an educational medium developed by the Indonesian Ministry of Health as a reference for adolescent health, including menstrual health information. This study aimed to evaluate the effect of menstruation education using Rapor Kesehatanku on knowledge and preparedness for menarche among 4th, 5th, and 6th-grade elementary school girls in Giriwangi Village, Gunungtanjung District, Tasikmalaya Regency. This study employed a pre-experimental design with a one-group pretest-posttest approach. The sample size was determined using total sampling because the accessible population was relatively small; therefore, all 42 eligible female students from SDN Poponcol and SDN Cikembang were included. The research instruments consisted of a 27-item menstruation knowledge questionnaire and a 22-item menarche preparedness questionnaire. The knowledge questionnaire had been tested for validity, with r-count greater than r-table (0.361), and demonstrated good reliability with a Cronbach’s alpha of 0.854. The preparedness questionnaire had also been tested for validity, with r-count greater than r-table (0.396), and showed excellent reliability with a Cronbach’s alpha of 0.936. The intervention consisted of menstruation education using Rapor Kesehatanku, followed by a post-test seven days after the intervention. Data were analysed using the Wilcoxon Signed Rank Test, and effect sizes were calculated using the formula r = Z/?N. The results showed a significant increase in students’ knowledge of menstruation after the intervention, with p < 0.001 and a large effect size (r = 0.69). The proportion of students with good knowledge increased from 14.3% before the intervention to 40.5% after the intervention. Preparedness for menarche also increased significantly, with p = 0.030 and a moderate effect size (r = 0.34). The proportion of students who were ready to face menarche increased from 81.0% to 95.2%. The use of Rapor Kesehatanku significantly improved knowledge and preparedness for menarche among elementary school girls. These findings indicate that Rapor Kesehatanku can be used as an effective promotive and preventive educational medium to support menstrual health education among adolescent girls.]]>
