Abstract
INTRODUCTION: Anemia continues to be a problem among adolescent girls, including in Indonesia. Although the Weekly Iron-Folic Acid Supplementation (WIFAS) program was introduced in 2014, adherence remains a challenge. The study aimed to evaluate the effectiveness of WhatsApp (WA) reminder messages in improving knowledge and adherence to WIFAS among adolescent girls in the Salahutu Sub-District, Maluku Province. METHODS: A quasi-experimental design was employed in 2024, utilizing a pretest-posttest control group framework across two senior high schools in Salahutu Sub-District. The intervention school (n = 49) received WA-based reminder messages for four weeks, while the control school (n = 42) continued to receive routine services. We used Mann-Whitney, Fisher Exact and chi-square tests in this analysis. RESULTS: The WA-based intervention led to a significant improvement in knowledge scores among adolescent girls from the intervention school (p < 0.001). These students were also more likely to have taken WIFAS in the week preceding the endline survey (p < 0.001) and to have consumed at least 75% of the distributed WIFAS (p = 0.015) compared to the control school. Furthermore, the mean hemoglobin levels were significantly higher in the intervention compared to the control school (p = 0.001). CONCLUSIONS: The WA-based reminder messages were effective in enhancing knowledge and adherence to WIFAS. Expanding this approach to a broader population is recommended before scaling up implementation across Maluku and other regions in Indonesia.