October 13, 2022

High-quality shared toilets could improve people’s quality of life and well-being— bringing benefits beyond any reduction in infectious diseases — according to a new study published in BMJ Open. The findings highlight the need to measure quality of life and well-being outcomes in future sanitation evaluations.

Dr. Joe Brown

Dr. Joe Brown

The research was conducted by the London School of Hygiene & Tropical Medicine (LSHTM) in collaboration with the Instituto Nacional de Saúde, Mozambique and the University of North Carolina at Chapel Hill. Joe Brown, PhD, associate professor in the Department of Environmental Sciences and Engineering at the UNC Gillings School of Global Public Health, was among the researchers who evaluated an intervention delivered by the non-governmental organization Water & Sanitation for the Urban Poor.

The study focused on the low-income urban neighborhood of Chamanculo in Maputo, the capital of Mozambique. Shared toilets are common in many informal settlements, like those in Chamanculo, when small dwellings do not have space for a private toilet or residents cannot afford one.

The study compared people who used higher-quality shared toilets, meaning pour-flush toilets with solid walls and doors,  to people who used existing pit latrines, which usually consist of a hole in the ground hidden by makeshift walls or sheeting.

Those with better toilets reported a large difference in sanitation-related quality of life, including reduced feelings of disgust and shame, and a small increase in general mental well-being, including feeling calm or cheerful.

The study is the first of its kind to evaluate the impact of an urban sanitation intervention on outcomes such as user-reported privacy, safety or mental well-being using a validated multidimensional measure. Known as sanitation-related quality of life (SanQoL), the measure provides a blueprint for others to more holistically compare the cost-effectiveness of different toilet options.

“This research suggests that quality of life outcomes can be improved by sanitation interventions, which is particularly relevant at a time when several trials have questioned the health effects of sanitation improvements,” said Ian Ross, PhD, lead study author and assistant professor of health economics at LSHTM. “If people consistently tell us they want better toilets to feel safer and have more privacy, we should be measuring which interventions improve those outcomes the most for a given cost, in addition to looking at disease.”

Inadequate sanitation facilities can have other negative consequences for health. When individuals are forced to use toilets that are dirty and lack privacy, the user’s safety and dignity can be compromised. Although previous research has highlighted this — for example, through focus group discussions — until now there has not been a transferable, evidence-based measure that integrates multiple quality of life outcomes using a small number of questions.

SanQoL outcomes include worrying about disgust, privacy, safety, health and shame. Qualitative studies find that toilet users often consider these matters more important than disease outcomes, such as a reduction in diarrhea. However, sanitation intervention evaluations often focus solely on assessing if improved toilets have reduced infectious disease.

To assess the impact of high-quality toilets on quality of life and mental well-being, the researchers interviewed two groups of people: those who used existing pit latrines (the control group) and those who had previously received high-quality shared toilets as part of a non-randomized trial (the intervention group). In total, 424 households were included in the study across 272 compounds. 130 compounds were in the control group and 142 were in the intervention group.

The groups were selected in a previous trial, known as the Maputo Sanitation trial, which took place from 2015 to 2018. Participants who received the high-quality toilets were chosen based on various criteria, including the number of inhabitants in the compound; availability of space; and willingness to contribute financially to the construction of the new toilets. Most of the same criteria were applied to the control group. The trial concluded that the intervention had no effect on any measure of child health, including diarrhea and nutritional outcomes.

SanQoL was used in the more recent study. It is measured a on a scale of 0-1, with higher scores equating to better outcomes. The five attributes (disgust, privacy, safety, health and shame) are weighted according to their perceived importance by toilet users. Individuals answer questions such as “Can you use the toilet in private, without being seen?” and use the responses: always, sometimes, rarely or never.

The research team also evaluated general mental well-being using the WHO-5 mental well-being index, a 0-100 scale that includes five questions relating to feeling cheerful, calm, active, well-rested and finding enjoyment in life.

The group with the high-quality toilets experienced a large gain in sanitation-related quality of life. They measured an average of 0.83 on the 0-1 SanQoL scale, compared to the pit latrine group at 0.49. The same group experienced a smaller gain in mental well-being, measuring 58.7 on the 0-100 WHO-5 mental well being index, compared to the pit latrine group at 54.4.

“Sanitation is about so much more than protection from infectious disease,” Brown said. “It’s about human dignity, privacy, safety and overall well-being. Showing that better sanitation can impact lives in a myriad of positive way helps make the policy case for more investment in critical infrastructure.”

This work was supported by the Economic and Social Research Council through a doctoral studentship. The fieldwork was funded by the Bill & Melinda Gates Foundation.

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