BACKGROUND Despite a strong theoretical rationale for combining water, sanitation and hygiene (WaSH) interventions to improve child health, study findings are heterogeneous with little understanding of the mechanisms for these effects. Our study objective was to demonstrate the utility of structural equation modeling (SEM) to assess intervention effects on height-for-age z score (HAZ) through the complex system of WaSH pathways. METHODS We used data from a matched cohort effectiveness evaluation of a combined on-premise piped water and improved sanitation intervention in rural Odisha, India. Height/length was measured in children 0-59 months old (n = 1826) from 90 matched villages in February-June 2016. WaSH behaviours and infrastructure were assessed through household surveys and observation, respectively. We used SEM to calculate the standardized path coefficients and the total contributions of WaSH pathways to HAZ. RESULTS Intervention improvements on HAZ were through the sanitation pathway (coverage → use β: 0.722; use → HAZ β: 0.116), with piped water coverage indirectly affecting HAZ through improved sanitation use (β: 0.148). Although the intervention had a positive association with handwashing station coverage, there was no evidence of a total hygiene pathway effect on HAZ or further direct effects through the water pathways. CONCLUSIONS This study demonstrates the utility of SEM to assess the mechanisms through which combined WaSH interventions impact HAZ as a system of pathways, providing a more nuanced assessment than estimation of the total intervention effect. Our finding, that water impacts HAZ through the sanitation pathway, is an important and actionable insight for WaSH programming.

中文翻译：

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使用结构方程模型来理清环境卫生、水和个人卫生途径，以干预改善 5 岁以下儿童的年龄别身高。

背景尽管将水、环境卫生和个人卫生（WaSH）干预措施结合起来以改善儿童健康有强有力的理论依据，但研究结果各不相同，对这些影响的机制知之甚少。我们的研究目的是展示结构方程模型 (SEM) 的实用性，以通过复杂的 WaSH 途径系统评估对年龄别身高 z 评分 (HAZ) 的干预效果。方法 我们使用了印度奥里萨邦农村地区自来水和改善卫生干预相结合的匹配队列有效性评估的数据。2016 年 2 月至 6 月，对来自 90 个匹配村庄的 0-59 个月大的儿童 (n = 1826) 进行了身高/身长测量。分别通过家庭调查和观察评估了 WaSH 行为和基础设施。我们使用 SEM 计算标准化路径系数和 WaSH 路径对 HAZ 的总贡献。结果 对 HAZ 的干预改善是通过卫生设施途径进行的（覆盖率 → 使用 β：0.722；使用 → HAZ β：0.116），自来水覆盖率通过改善卫生设施使用间接影响 HAZ（β：0.148）。尽管干预措施与洗手站覆盖率呈正相关，但没有证据表明总体卫生途径对 HAZ 产生影响或通过水途径产生进一步的直接影响。结论 本研究证明了 SEM 的实用性，可以评估联合 WaSH 干预措施作为路径系统影响 HAZ 的机制，提供比总干预效果估计更细致的评估。我们的发现是，水通过卫生设施途径影响 HAZ，这对于 WaSH 规划来说是一个重要且可操作的见解。