Assessing the Impact of Teacher-Led School-based Hygiene Intervention on Children's Handwashing Practices for Childhood Disease Prevention in Lagos, Nigeria: A Cluster Randomised Control Trial

Background Poor hand hygiene contributes significantly to preventable childhood diseases in Nigeria. Teacher-led school-based interventions offer a promising approach to improve childhood hygiene behaviours. This study assesses the impact of such an intervention on handwashing practices among schoolchildren in Lagos, Nigeria. Methods A cluster randomised controlled trial was conducted from January to October 2024 among 3,458 pupils (primaries 1–6) in 50 schools across four LGAs in Lagos State. 25 schools received the teacher-led WASHED-UP hygiene intervention, while 25 served as controls. Data on handwashing knowledge, practices, and absenteeism were collected at baseline and endline using structured questionnaires and observational checklists. Intervention effects were analysed using multilevel mixed-effects linear and logistic regression models, adjusting for clustering and baseline covariates (p < 0.05). Results Although 50 schools were initially enrolled as planned, 5 withdrew after baseline, resulting in 45 schools with 2,300 pupils included in the analysis. Therefore, of the eligible schools, 45 participated (25 intervention, 20 control), enrolling 2,300 pupils at baseline (mean age = 8.4 ± 1.8 years). Baseline knowledge scores were slightly higher in the control group (20.26 ± 3.29) than in the intervention group (19.81 ± 3.31; p = 0.001). At endline, knowledge scores were comparable (control: 19.91 ± 3.54; intervention: 20.08 ± 2.99; p = 0.246). Handwashing practice scores improved in both groups but were significantly higher in the intervention group at both baseline (16.26 ± 3.28 vs 14.22 ± 2.93; p < 0.001) and endline (16.81 ± 3.81 vs 14.94 ± 4.55; p < 0.001). The proportion of pupils with good handwashing practice increased from 32.0% to 40.7% in the intervention group, compared to 8.4% to 26.5% in the control group (χ² = 63.1; p < 0.001). Correlation between knowledge and practice strengthened post-intervention (r = 0.51; p < 0.001), indicating positive behavioural change. Conclusions The study showed that school-based interventions have a significant impact on shaping health behaviours and promoting child well-being. It unravels the importance of integrating structured WASH education into Nigeria’s primary school curriculum as a scalable strategy to improve hygiene practices and reduce the burden of preventable diseases among school-aged children.