title: Tracking progress towards global drinking water and sanitation targets: A within and among country analysis.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, United States. Electronic address: jafuller@umich.edu.
authors.forename: James A
authors.initials: JA
authors.lastname: Fuller
authors.affiliation: Department of Emergency Medicine, University of Michigan, Ann Arbor, MI, United States.
authors.forename: Jason
authors.initials: J
authors.lastname: Goldstick
authors.affiliation: The Water Institute, Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.
authors.forename: Jamie
authors.initials: J
authors.lastname: Bartram
authors.affiliation: Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, United States.
authors.forename: Joseph N S
authors.initials: JNS
authors.lastname: Eisenberg
keywords: Drinking water; Global monitoring; Policy; Sanitation