Developing and evaluating a mobile application-based intervention to support HPV-tested women and increase their retention to follow-up: a mixed-methods implementation study - PROJECT SUMMARY/ABSTRACT Cervical cancer (CC) is one of the leading causes of cancer death among women from Latin America. In the Region, screening programs face important problems to assure follow-up/treatment, which is a major obstacle for screening effectiveness. Human papillomavirus (HPV) testing has become the main strategy to reduce the burden of the disease. However, HPV positivity can have an important negative impact on the psychosocial health of tested women. In addition, for many Latin-American women, information provided by health providers about HPV is often confusing; women have difficulties in understanding HPV-test results and steps to follow. Both HPV’s psychosocial impact of HPV-testing, and lack of information regarding the follow-up process might not only diminish women's quality of life but also reduce their retention to follow up. The specific aims of this project are the following: AIM 1. To develop and test usability of an app to increase women knowledge about HPV/ CC/FU, reduce the psycho-social impact of HPV-testing and increase retention to follow-up. (R21 phase) AIM 2. To evaluate the implementation strategy and preliminary effectiveness outcomes of the app-based intervention and identify barriers and facilitators to the implementation. (R33 Phase) We will carry out a pilot implementation study of an app-based intervention aimed at providing HPV-tested with evidence-based information about HPV, reducing the psycho-social impact of HPV and increasing retention to follow-up. The app-based intervention will consist of an app to provide information and support to HPV-tested women, offered to women by trained health providers during the screening consultation.We will combine a user-centered design approach with behavioral models and Implementation Science frameworks to test, and evaluate the implementation strategy of the app-based intervention in PHC centers in Argentina. We will use a mixed methods descriptive design, composed of a quantitative Women study and a Quantitative -qualitative Study at Health provider level. Following Proctor´s taxonomy, in the Women Study we will evaluate acceptability, appropriateness, and adoption of the implementation strategy. To measure preliminary effectiveness outcomes we will carry out three quantitative surveys at different moments of the screening/follow-up process and we will analyze data from routine clinical records. In the Study of Health providers, we will carry out semi-structured interviews to analyze CFIR selected constructs. This study will provide evidence about the implementation strategy of an app-based intervention that will be ready for evaluation of its effectiveness in a randomized controlled trial. It will constitute a solid and sound example of how Implementation Science can be used to produce rigorous evidence-based information about implementation of mHealth interventions for cancer control.