How does Community-Led Total Sanitation (CLTS) promote latrine construction, and can it be improved? A cluster-randomized controlled trial in Ghana

Rationale: Open defecation is connected to poor health and child mortality, but billions of people still do not have access to safe sanitation facilities. Community-Led Total Sanitation (CLTS) promotes latrine construction to eradicate open defecation. However, the mechanisms by which CLTS works and how they can be improved remain unknown. The present study is the first to investigate the psychosocial determinants of CLTS in a longitudinal design. Furthermore, we tested whether CLTS can be made more effective by theory- and evidence-based interventions using the risks, attitudes, norms, abilities, and selfregulation (RANAS) model. Methods: A cluster-randomized controlled trial of 3216 households was implemented in rural Ghana. Communities were randomly assigned to classic CLTS, one of three RANAS-based interventions, or to the control arm. Prepost surveys at 6-month follow-up included standardized interviews assessing psychosocial determinants from the RANAS model. Regression analyses and multilevel mediation models were computed to test intervention effects and mechanisms of CLTS. Results: Latrine coverage increased pre-post by 67.6% in all intervention arms and by 7.9% in the control arm (p < .001). The combination with RANAS-based interventions showed non-significantly greater effects than CLTS alone. The effects of CLTS on latrine construction were significantly mediated by changes in four determinants: others' behaviour and approval, self-efficacy, action planning and commitment. Changes in vulnerability, severity, and barrier planning were positively connected to latrine construction but not affected by CLTS. Conclusion: This study corroborates the effectiveness of CLTS in increasing latrine coverage, and additional activities can be improved further. Behaviour change techniques within CLTS that strengthened the relevant factors should be maintained. The study also recommends interventions based on the RANAS approach to improve CLTS. Further research is needed to understand the effects of RANAS-based interventions combined with CLTS at longer follow-up.