Impact of a school-based water and hygiene intervention on child health and school attendance in Addis Ababa, Ethiopia: a cluster-randomised controlled trial
Authors: Bick Sarah , Ezezew Alem , Opondo Charles , Leurent Baptiste , Argaw Wossen , Hunter Erin C , Cumming Oliver , Allen Elizabeth , Dreibelbis Robert 
Published: April 2024

SummaryBackgroundWater, sanitation and hygiene (WASH) interventions in schools may improve the health and school attendance of schoolchildren, particularly among post-menarcheal girls, but existing evidence is mixed. We examined the impact of an urban WASH in schools programme (Project WISE) on child health and attendance.MethodsThe WISE cluster-randomised trial, conducted in 60 public primary schools in Addis Ababa, Ethiopia over one academic year, enrolled 2–4 randomly selected classes per school (approximately 100 pupils) from grades 2–8 (aged 7–16) in an ’open cohort’. Schools were assigned 1:1 by stratified randomisation to receive the intervention during the 2021/22 academic year or the 2022/23 academic year (waitlist control). Masking was not possible. The intervention included improvements to drinking water storage, filtration and access, alongside handwashing stations and behaviour change promotion. Planned improvements to sanitation facilities were not realised. At four unannounced classroom visits between March and June 2022 (post-intervention, approximately every four weeks), enumerators recorded primary outcomes of roll-call absence, and pupil-reported respiratory illness and diarrhoea in the past seven days among pupils present. Analysis was by intention-to-treat. This study is registered with ClinicalTrials.gov, numberNCT05024890.FindingsOf 83 eligible schools, 60 were randomly selected and assigned. In total, 6229 eligible pupils were enrolled (median per school 101·5; IQR 94–112), with 5987 enrolled at study initiation (23rd November–22nd December 2021) and the remaining 242 during follow-up. Data were available on roll-call absence for 6166 pupils (99·0%), and on pupil-reported illness for 6145 pupils (98·6%). We observed a 16% relative reduction in the odds of pupil-reported respiratory illness in the past seven days during follow-up in intervention schools vs. control schools (aOR 0·84; 95% CI 0·71– 1·00; p=0·046). No effect was observed on pupil-reported diarrhoea in the past seven days (aOR 1·15; 95% CI 0·84–1·59; p=0·39) nor roll-call absence (aOR 1·07; 95% 0·83–1·38; p=0·59). There was a small increase in menstrual care self-efficacy (aMD 3·32 on 0–100 scale; 95% CI 0·05–6·59), and no effects on the other health, wellbeing and absence secondary outcomes.InterpretationThis large-scale intervention to improve WASH conditions in schools across a large city had a borderline impact on respiratory illness among schoolchildren but no effect on diarrhoeal disease nor pupil absence. Future research should establish the relationships between WASH-related illness and absence and other downstream educational outcomes.FundingChildren’s Investment Fund Foundation.Panel:Research in contextEvidence before this studyPrior to this study, there were several systematic reviews on water, sanitation and hygiene (WASH) in schools, none of which used meta-analysis methods due to heterogeneity in intervention components and outcome measures. In the most comprehensive review in 2019, McMichael reported mixed evidence for the effectiveness of WASH in schools in low-income countries across health and educational outcomes, and randomised and non-randomised studies. Prior to starting this trial, there were two randomised trials conducted exclusively in urban schools in a low- or middle-income country: a handwashing trial in Cairo, Egypt examining absence due to influenza, and a trial of hand sanitizer and respiratory hygiene in Dhaka, Bangladesh for reducing influenza-like illness and laboratory-confirmed influenza. During this study, another randomised trial in Manila, Philippines was published, with different outcomes (malnutrition and dehydration). The effectiveness of combined water, sanitation and hygiene in urban schools on respiratory illness, diarrhoea and overall absence was not known, and some previous evaluations have used school records alone to track attendance. Previous studies evaluating WASH in schools interventions have suggested that multi-component interventions may be more effective, and that specific effects on girls’ absence might be observed with provision of a safe, private space to change menstrual materials.Added value of this studyThis study provides rigorous experimental evidence on the effectiveness of an urban school-based water and hygiene intervention in reducing pupil-reported respiratory illness among schoolchildren, during the COVID-19 pandemic. There was no evidence of effects on pupil-reported diarrhoea or absence, nor gender-specific effects on absence. We highlight the value of unannounced visits for absence tracking with comparison to pupil-reported absence, and the need to distinguish seasonal and pandemic illness in future trials.Implications of all the available evidenceOur results are consistent with the mixed impacts on health and absence found in previous WASH in schools evaluations. The lack of detected effects on diarrhoea, attendance and secondary outcomes related to wellbeing and menstrual health should be considered in light of the absence of sanitation infrastructure improvements, which were not delivered until after trial completion, which may have influenced risk of diarrhoeal disease. Nonetheless, school absence is multi-factorial, and these findings temper expectations that absence can be impacted by reductions in one domain of illness and not the many other important drivers linked to poverty and gender, and few programmes are likely to be able to obtain a more ambitious infrastructure and behaviour change programme at the scale of the one included in this trial, which is currently being replicated in other cities across Ethiopia.