Integrating behavioural science and design thinking to develop a water treatment innovation in Malawi healthcare: a case study of the intervention design process.

Access to safe water is essential for maternal and neonatal care, yet many healthcare facilities (HCFs) in low- and middle-income countries (LMICs) face severe water scarcity, undermining service delivery and patient outcomes. Malawi exemplifies this challenge. While technologies such as solar disinfection of harvested rainwater (HRW-SODIS) offer potential solutions, mere deployment does not guarantee adoption or sustainability. This study reports on experiences and lessons learned from the design of the SURG-Water project, which is testing, for the first time, the application of HRW-SODIS in clinical settings. Rather than focusing solely on technical performance, the project employed a co-design process grounded in behavioural science and design thinking to align both the technology and its deployment strategy with facility workflows, user preferences and socio-cultural norms. Two maternal HCFs were purposively selected for the pilot, and a participatory design process involving health workers, community leaders and government stakeholders guided iterative HRW-SODIS system development. Site assessments, interviews, and focus groups revealed behavioural, infrastructural, and institutional factors that shaped design choices. This process produced not just a water treatment solution, but an integrated strategy including staff training, educational materials, and community sensitisation. The work demonstrates a clear pathway from scientific concept to contextually grounded intervention design. The SURG-Water model offers a replicable example of how interdisciplinary, user-centred methods can be used to bridge knowledge and practice in resource-constrained healthcare settings. While SODIS has existed for years, it remains underused; this approach provides a practical step toward addressing real-world barriers to uptake, starting from its design.