CLTS implementation in Malawi: process evaluation of a sanitation and hygiene intervention

Community-Led Total Sanitation (CLTS) seeks to eliminate open defecation by empowering households to adopt improved sanitation and hygiene behaviours through latrine use. Widely integrated into national sanitation strategies in low- and middle-income countries, CLTS is implemented through pre-triggering, triggering, and post-triggering activities. However, limited evidence exists on how implementation process promotes behaviour change. This study retrospectively evaluates a community-based intervention in Chiradzulu District, Malawi, that employed CLTS alongside market-based sanitation and hygiene promotion campaigns. Using the UK Medical Research Council process evaluation framework, we analysed project documentation and collected data from household surveys (n=1,151), interviews (n=36), and focus group discussions (n=14). All planned activities were implemented, though adaptations affected fidelity and required additional household visits. Intervention reach was suboptimal: 46% of households attended triggering events, 64% received visits, 16% were exposed to market-based sanitation, and 47% received hygiene campaigns. Exposure to both triggering sessions and household visits increased the likelihood of latrine availability (OR = 1.63; CI = 1.55–1.72) and HWF presence (OR = 1.39; CI = 1.03–1.86). High costs, limited awareness of masons, and extreme weather events affected latrine adoption. Our findings emphasize the need for multi-level engagement, flexible delivery, and addressing barriers for sustainable sanitation adoption.