Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, United States.
Department of Emergency Medicine, University of Michigan, Ann Arbor, MI, United States.
Sci Total Environ. 2016 Jan 15;541:857-864. doi: 10.1016/j.scitotenv.2015.09.130. Epub 2015 Oct 2.
Global access to safe drinking water and sanitation has improved dramatically during the Millennium Development Goal (MDG) period. However, there is substantial heterogeneity in progress between countries and inequality within countries.
We assessed countries' temporal patterns in access to drinking water and sanitation using publicly available data. We then classified countries using non-linear modeling techniques as having one of the following trajectories: 100% coverage, linear growth, linear decline, no change, saturation, acceleration, deceleration, negative acceleration, or negative deceleration. We further assessed the degree to which temporal profiles follow a sigmoidal pattern and how these patterns might vary within a given country between rural and urban settings.
Among countries with more than 10 data points, between 15% and 38% showed a non-linear trajectory, depending on the indicator. Overall, countries' progress followed a sigmoidal trend, but some countries are making better progress and some worse progress than would be expected. We highlight several countries that are not on track to meet the MDG for water or sanitation, but whose access is accelerating, suggesting better performance during the coming years. Conversely, we also highlight several countries that have made sufficient progress to meet the MDG target, but in which access is decelerating.
Patterns were heterogeneous and non-linearity was common. Characterization of these heterogeneous patterns will help policy makers allocate resources more effectively. For example, policy makers can identify countries that could make use of additional resources or might be in need of additional institutional capacity development to properly manage resources; this will be essential to meet the forthcoming Sustainable Development Goals.
在千年发展目标（MDG）期间，全球获得安全饮用水和卫生设施的情况有了显著改善。然而，各国之间的进展存在很大差异，国家内部也存在不平等现象。
我们利用公开数据评估了各国在获得饮用水和卫生设施方面的时间模式。然后，我们使用非线性建模技术将各国分类为以下轨迹之一：100%覆盖、线性增长、线性下降、无变化、饱和、加速、减速、负加速或负减速。我们进一步评估了时间曲线遵循类正态分布的程度，以及这些模式在给定国家的农村和城市环境中可能如何变化。
在拥有超过 10 个数据点的国家中，根据指标的不同，有 15%到 38%的国家呈现出非线性轨迹。总体而言，各国的进展呈现出类正态分布趋势，但有些国家的进展比预期的要好，而有些则更差。我们强调了几个没有达到 MDG 水或卫生目标的国家，但它们的饮用水供应正在加速，这表明在未来几年内表现会更好。相反，我们还强调了几个已经取得足够进展以达到 MDG 目标但饮用水供应正在减速的国家。
模式存在异质性，而且非线性很常见。对这些异质模式的描述将有助于政策制定者更有效地分配资源。例如，政策制定者可以确定哪些国家可能需要额外的资源，或者可能需要额外的机构能力发展来妥善管理资源；这对于实现即将到来的可持续发展目标至关重要。
