Participatory design approaches to develop global health interventions have gained traction in recent years. However, while broad frameworks for the application of design approaches exist, literature outlining concrete experiences of and guidance for navigating specific design challenges remains limited. This article proposes a design framework based on our own experiences when applying human-centered design principles to bolster sustainable hypertension medication financing in rural Uganda. In our case study, we embedded an mHealth platform within a community-led health intervention aiming to fund blood pressure medication through a shared financial pooling system. Over the course of this project and in close collaboration with intervention end-users, we developed a design framework that outlines challenges, decision-making processes, and design solutions. We iteratively refined the framework between November 2021 and April 2023 over two phases of extensive formative research and one phase of structured qualitative data collection, consisting of 55 in-depth interviews and 4 focus group discussions with clients with hypertension, health care providers, and key intervention stakeholders. The resulting MILEPOST framework consists of 7 domains to consider amid mHealth intervention co-development: medical (e.g., health challenge scope and management); interpersonal (e.g., communication, decision-making, and trust within and across communities); logistical (e.g., current processes and sustainable implementation pathways); ethical (e.g., research and implementation ethics); political (e.g., stakeholder buy-in and long-term support); scientific (e.g., rigorous and feasible approaches for data collection, management, and analysis); and technical (e.g., mHealth component development, refinement, and implementation). We define each domain, provide examples of design challenges and derived solutions as they emerged in our work, and outline starting points for operationalizing each domain in other contexts or studies. We discuss how MILEPOST can provide guidance to researchers and implementors by contributing specific and actionable insights for participatory health intervention design efforts.
