Effectiveness-implementation trial of an intervention to improve access to and use of family planning services - Women in rural areas face challenges to using contraception. Our and others’ studies emphasize the key facilitating role of positive peer support for helping women navigate myriad challenges when they desire pregnancy prevention. Despite such documented benefits, tested approaches to deploying experienced contraception users to provide social support to other women are lacking. We developed the “I-CAN” intervention to train and deploy experienced users of contraception as “mentors” who provide tailored informational, instrumental, appraisal, and emotional support to other women (“mentees”) on contraception. I-CAN was co-developed with community advisory boards and health officials in rural areas via participatory human-centered design. I-CAN mentors are local women with experience with multiple contraceptive methods, including self-injection (a novel yet underused self-care method). Underpinned by multiple theories, I-CAN is designed to increase women’s contraceptive knowledge, agency over contraceptive decision-making, and ability to access contraception, resulting in our primary objective of increasing women’s ability to overcome barriers to contraceptive use. Mentors are trained to provide neutral support and respect women’s decisions about contraception without being directive. After promising findings in our pilot study, we propose to build on our strong, ongoing partnership to test I-CAN on a larger scale. In Aim 1, we will test the effectiveness of I-CAN in a hybrid (type 2) effectiveness-implementation cluster-randomized controlled trial, randomizing 52 rural areas 1:1 to receive I-CAN or not. We will compare contraceptive use (primary endpoint), contraceptive agency, method satisfaction, and use of self-injection after 24 months between arms. Data will be collected via repeated cross-sectional household surveys (N=1,560 each time). In Aim 2, we will examine the process of implementing I-CAN, guided by the PRISM/RE-AIM framework. In Aim 3, we will estimate the incremental cost-effectiveness ratio of I-CAN relative to standard of care using each of our primary and secondary endpoints as effectiveness measures and measuring costs from an implementation perspective. I-CAN holds promise for helping women overcome contraceptive use barriers.