Unequal geographic distribution of water and sanitation at the household and school level in Sudan.

The Sudanese Government launched the National SDG-6 Plan and commences its implementation to achieve and sustain universal and equitable access to basic WASH services by 2030. It is critical to understand the geographical heterogeneity of Sudan and patterns in the inequality of access to safe drinking water and sanitation. Through such research, the disease control strategy can be optimized, and resource allocation can be prioritized. We explored spatial heterogeneity and inequality in access to improved water and sanitation across Sudan by mapping the coverage at both the state and district levels. We decomposed the inequality across Sudan into within-state, between-state, within-district, and between-state inequalities using the Theil L and Theil T indices. We calculated the Gini coefficient to assess the inequality of access to improved water and sanitation, based on the deviation of the Lorenz curve from the line of perfect equality. The study population was 105,167 students aged 8-13 at 1,776 primary schools across the country. Geographical heterogeneity was prominent in the Central Darfur, South Darfur, East Darfur, Kassala, West Kordofan, and Blue Nile States, all of which showed severe inequality in access to an improved latrine at the household level in terms of the Theil T or Theil L index. The overall inequality in the coverage of improved sanitation went beyond the warning limit of 0.4 for the Gini coefficient. The inequality in terms of the Theil L and Theil T indices, as well as the Gini coefficient, was always higher for improved sanitation than for improved water at the household level. Within-state inequality accounted for 66% or more of national inequalities in the distribution of improved sanitation and drinking water for both the Theil L and Theil T indices. This is the first study to measure geographical heterogeneity and inequalities in improved water and sanitation coverage across Sudan. The study may help to prioritize resource allocation to areas with the greatest water and sanitation needs.

Assessment of social network change in a national longitudinal survey.

OBJECTIVES: This article describes new longitudinal data on older adults' egocentric social networks collected by the National Social Life, Health, and Aging Project (NSHAP). We describe a novel survey technique that was used to record specific personnel changes that occurred within respondents' networks during the 5-year study period, and we make recommendations regarding usage of the resulting data. METHOD: Descriptive statistics are presented for measures of network size, composition, and structure at both waves, respondent-level summary measures of change in these characteristics between waves, as well as measures that distinguish between changes associated with losses of Wave 1 network members, additions of new ones, and changes in relationships with network members who were present at both waves. RESULTS: The NSHAP network change module was successful in providing reliable information about specific changes that occurred within respondents' confidant networks. Most respondents lost at least one confidant from W1 and added at least one new confidant between waves as well. Network growth was more common than network shrinkage. Both lost and new ties were weaker than ties that persisted throughout the study period. DISCUSSION: These data provide new insight into the dynamic nature of networks in later life, revealing norms of network turnover, expansion, and weakening. Data limitations are discussed.