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 (beta = 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 (beta = 0.016 [-0.039, 0.072] p = 0.56) or the HP&WT and sanitation intervention (beta = 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.