Assessing peri-urban sanitation quality using a theoretically derived composite measure in Lusaka, Zambia

Despite ongoing debates about what constitutes adequate sanitation, there is a lack of sanitation quality measures that are theoretically grounded in ways that allow empirical comparisons of quality across different types of sanitation. The Healthy Sanitation Framework (HSF) was developed to capture universal aspects of sanitation quality from a public health perspective. From this, the Peri-Urban Healthy Toilet Index (PUHTI) was created for measuring on-site, peri-urban sanitation quality. This PUHTI score was used to assess sanitation quality in a peri-urban area in Lusaka, Zambia. The HSF identified five categories for capturing sanitation quality: hygiene, use, sustainability, desirability, and accessibility. A composite index derived from these categories had high reliability and plausible validity, despite barriers to rigorously evaluating validity. Applying the PUHTI tool showed that while 87% of toilets were classified as ‘improved, but shared,’ there were frequent concerns about doors that could not be locked, dirty user interfaces, unhygienic containment, limited emptyability, and lack of handwashing facilities. The HSF allows granular measures of sanitation quality to be developed in any setting using a reproducible and theoretically grounded process. However, lack of a unified basis on which to compare different types of sanitation overall or evidence to compare within narrower categories currently limits comparisons across types of sanitation.