Drinking water and sanitation: progress in 73 countries in relation to socioeconomic indicators

Introduction The United Nations recognizes the basic human right to water and sanitation. (1,2) Accordingly, the international community, through the recent adoption of the Sustainable Development Goals (SDGs), has made a commitment to achieve universal and equitable access to safe drinking water and adequate sanitation by 2030. (3) The SDGs build on the Millennium Development Goal (MDG) target (4) to halve, between 1990 and 2015, the proportion of the population without access to safe water and basic sanitation. During the MDG period, some countries have made substantial progress, while others have stagnated. (5) The national characteristics that may enhance or hinder progress on water and sanitation are poorly understood. For example, external finance should make it easier for governments to improve drinking water and sanitation coverage. While a positive correlation between aid received and improvements in such coverage has been observed in some studies, (6,7) other studies have not detected such a relationship. (8-11) The differing results may be due to limitations in the methods used (8) and/or the choice of indicator used to measure progress. Progress has been measured as population access to improved drinking water and sanitation--or the change in such access over a specified period. However, changes in population access are not necessarily comparable across different countries because, as a country approaches universal access, it becomes increasingly difficult to reach those who still lack access. The aim of the present study is to determine whether progress in improving access to improved drinking water and sanitation, achieved by countries between 2000 and 2012, is associated with national socioeconomic characteristics. We used a new indicator of progress--the normalized rate of change in access--to allow countries to be compared, regardless of their initial coverage levels. Methods Data sources We obtained estimates of the percentage of national populations with access to improved sanitation and water--for various years between 2000 and 2012--from the 2013 Country Files of the Joint Monitoring Programme for Water Supply and Sanitation (12)--which were the most up-to-date information available at the time of analyses. This World Health Organization/United Nations Children's Fund programme compiles the results of nationally representative surveys, including Demographic and Health Surveys, Multiple Indicator Cluster Surveys, World Health Surveys and national censuses. We considered only data from 2000 onwards to reflect the progress countries made since the MDGs were set in the year 2000. We included shared toilet facilities in our improved-sanitation category because data for both shared sanitation and total improved sanitation including shared sanitation--i.e. the two data sets needed to investigate total improved sanitation excluding shared sanitation--were only available for four of our study countries. The Joint Monitoring Programme currently discounts shared sanitation from total improved sanitation by applying a fixed ratio for each country. (13) However, since these ratios are based on data that may have been collected before 2000 and, for some countries, are based on a single data point, we decided not to use them--or any other similar correction factor--in our analyses. We included countries with at least five data points that covered at least three different years. Multiple survey data points from any one year were treated independently. Indicator of progress To compare countries with differing initial levels of population access to improved sanitation and water, we defined the progress of country i as its normalized rate of change in access: normalized [rate.sub.i,j] = [rate.sub.i,j] - min. [rate.sub.j]/ max. [rate.sub.j] - min. [rate.sub.j] (1) where normalized [rate.sub.i,j] is the normalized rate of change for country i that had a baseline coverage level j in the year 2000; [rate. …