Trop Med Int Health. 2014 Jan;19(1):2-13. doi: 10.1111/tmi.12220.
Initiatives to monitor progress in health interventions like sanitation are increasingly focused on disparities in access. We explored three methodological challenges to monitoring changes in sanitation coverage across socio-economic and demographic determinants: (i) confounding by wealth indices including water and sanitation assets, (ii) use of individual urban and rural settings versus national wealth indices and (iii) child-level versus household-level analyses.
Sanitation coverage by wealth for children and households across settings was estimated from recent Demographic and Health Surveys in six low-income countries. Household assignment to wealth quintiles was based on principal components analyses of assets. Concordance in household quintile assignment and estimated distribution of improved sanitation was assessed using two wealth indices differing by inclusion or exclusion of water and sanitation assets and independently derived for each setting. Improved sanitation was estimated using under five children and households.
Wealth indices estimated with water, and sanitation assets are highly correlated with indices excluding them but can overstate disparities in sanitation access. Independently, derived setting wealth indices highly correlate with setting estimates of coverage using a single national index. Sanitation coverage and quintile disparities were consistently lower in household-level estimates.
Standard asset indices provide a reasonably robust measure of disparities in improved sanitation, although overestimation is possible. Separate setting wealth quintiles reveal important disparities in urban areas, but analysis of setting quintiles using a national index is sufficient. Estimates and disparities in household-level coverage of improved sanitation can underestimate coverage for children under five.
监测卫生干预措施（如环境卫生）进展的举措越来越关注获取方面的差异。我们探讨了监测社会经济和人口决定因素中环境卫生覆盖范围变化的三种方法学挑战：（i）财富指数（包括水和环境卫生资产）的混杂，（ii）使用个别城市和农村环境与国家财富指数，以及（iii）儿童层面与家庭层面的分析。
从六个低收入国家最近的人口与健康调查中，估计了不同环境中儿童和家庭的按财富划分的环境卫生覆盖率。根据资产主成分分析，将家庭分配到财富五分位数中。通过比较两种不同的财富指数，评估了家庭五分位数分配和改进环境卫生的估计分布之间的一致性，这两种指数分别包括或排除了水和环境卫生资产，并且是为每个环境独立推导的。使用五岁以下儿童和家庭估计了改进的环境卫生。
纳入或排除水和环境卫生资产的财富指数与不纳入这些资产的指数高度相关，但可能夸大了环境卫生获取方面的差异。独立推导的环境财富指数与使用单一国家指数的环境覆盖估计值高度相关。家庭层面估计的环境卫生覆盖率和五分位数差异始终较低。
标准资产指数提供了一个合理的改进环境卫生差异的衡量标准，尽管存在高估的可能性。单独的环境五分位数揭示了城市地区的重要差异，但使用国家指数分析环境五分位数就足够了。对五岁以下儿童改进环境卫生的家庭层面覆盖率的估计和差异可能会低估覆盖率。
