A cluster-randomized trial assessing the impact of school water, sanitation and hygiene improvements on pupil enrolment and gender parity in enrolment

We employed a cluster-randomized trial design to measure the impact of a school-based water, sanitation and hygiene (WASH) improvement on pupil enrolment and on gender parity in enrolment, in primary schools in Nyanza Province, Kenya (2007–2009). Among schools with poor water access during the dry season, those that received a water supply, hygiene promotion and water treatment (HP&WT) and sanitation improvement demonstrated increased enrolment (β = 0.091 [0.009, 0.173] p = 0.03), which translates to 26 additional pupils per school on average. The proportion of girls enrolled in school also increased by 4% (prevalence ratio (PR) = 1.04 [1.00, 1.07] p = 0.02). Among schools with better baseline water access during the dry season (schools that did not receive a water source), we found no evidence of increased enrolment in schools that received a HP&WT intervention (β = 0.016 [–0.039, 0.072] p = 0.56) or the HP&WT and sanitation intervention (β = 0.027 [–0.028, 0.082] p = 0.34), and there was no evidence of improved gender parity (PR = 0.99 [0.96, 1.02] p = 0.59, PR = 1.00 [0.97, 1.02] p = 0.75, respectively). Our findings suggest that increased school enrolment and improved gender parity may be influenced by a comprehensive WASH programme that includes an improved water source; schools with poor water access during the dry season may benefit most from these interventions.