Evaluating the sustainability and impact of a three-year point-of-use water treatment and handwashing intervention in rural Guatemala

Background: The promotion of point-of-use water treatment and handwashing with soap has led to large reductions in child diarrhea in randomized efficacy trials. We know little about the sustainability of behavior change and health benefits after the conclusion of intervention activities.

Methods: We present an extension of previously published design (propensity score matching) and analysis (targeted maximum likelihood estimation) methods to evaluate the sustainability and health impacts of a pre-existing (non-randomized) intervention (a three-year, combined point-of-use water treatment and handwashing campaign in rural Guatemala). Six months after the intervention, we conducted a cross-sectional cohort study in 30 villages (15 intervention, 15 control) that included 600 households and 929 children under five years old.

Results: The design created a sample of intervention and control villages that were comparable across more than 30 potentially confounding characteristics. The intervention was associated with modest gains in confirmed water treatment behavior (risk difference=0.05, 95%CI 0.02-0.09). We found, however, no differences between the intervention and control villages in self-reported handwashing behavior, spot-check hygiene conditions, the prevalence of either child diarrhea or clinical acute lower respiratory infections, or child growth.

Conclusions: To our knowledge this is the first post-intervention follow-up study of a combined point-of-use water treatment and handwashing behavior change intervention, and the first post-intervention follow-up of either intervention type to include child health measurement. Our findings highlight the difficulty of sustaining behavior-based point-of-use water treatment and handwashing outside of intensive efficacy trials.