Thammaraksa P.Powwattana A.Boonlue S.Meeklinhom Y.Mahidol University2025-07-252025-07-252025-07-01International Journal of Community Based Nursing and Midwifery Vol.13 No.3 (2025) , 180-19023222476https://repository.li.mahidol.ac.th/handle/123456789/111365Background: Multiple risk behaviors (MRB) among adolescents are correlated with adverse health outcomes. We have devised and examined the effect of a mobile application, STOP Multiple Risk Behaviors (“STOPMRB”), on perceived behavioral control and intention to avoid multiple risk behaviors (MRB) among Thai female adolescents. Methods: We conducted a two-group pre-post-test, quasi-experimental study involving Thai female adolescents aged 13–15 (N=60) in Samut Prakarn province, Thailand, between March and May 2021. Participants selected for the intervention group (N=30) were provided with access to a mobile application in conjunction with text messages for 8 weeks, whereas the control group (N=30) received standard education curricula. The primary outcome was self-reported risk behaviors. Secondary outcomes encompassed perceived behavioral control and intention to avoid MRB. Outcomes were analyzed using repeated measures ANOVA, Bonferrini test, Fisher’s Exact test, and independent t-test through the software IBM SPSS version 28. A significance level was established at a P-value of less than 0.05. Results: Following a two-month intervention, no MRB was reported among the intervention group, whereas the control group showed 6.7% (P=0.492). The intervention group demonstrated significantly higher mean scores of perceived behavioral control (P<0.001) and the intention to avoid (P<0.001) in comparison to the control group at weeks 4 and 8. Conclusion: Mobile application, according to STOPMRB, could enhance perceived behavioral control and intention to evade MRB and less self-reported frequency of MRB.NursingMedicineSocial SciencesArticleSCOPUS10.30476/ijcbnm.2025.104901.26672-s2.0-10501088583023224835