1,721,003 research outputs found
Coming home to die? The association between migration and mortality in rural South Africa
Full text linkBackground: studies on migration often ignore the health and social impact of migrants returning to their rural communities. Several studies have shown migrants to be particularly susceptible to HIV infection. This paper investigates whether migrants to rural households have a higher risk of dying, especially from HIV, than non-migrants.Methods: using data from a large and ongoing Demographic Surveillance System, 41,517 adults, enumerated in bi-annual rounds between 2001 and 2005, and aged 18 to 60 years were categorized into four groups: external in-migrants, internal migrants, out-migrants and residents. The risk of dying by migration status was quantified by Cox proportional hazard regression. In a sub-group analysis of 1212 deaths which occurred in 2000 – 2001 and for which cause of death information was available, the relationship between migration status and dying from AIDS was examined in logistic regression.Results: in all, 618 deaths were recorded among 7,867 external in-migrants, 255 among 4,403 internal migrants, 310 among 11,476 out-migrants and 1900 deaths were registered among 17,771 residents. External in-migrants were 28% more likely to die than residents [adjusted Hazard Ratio (aHR) = 1.28, P < 0.001, 95% Confidence Interval (CI) (1.16, 1.41)]. In the sub-group analysis, the odds of dying from AIDS was 1.79 [adjusted Odd ratio (aOR) = 1.79, P = 0.009, 95% CI (1.15, 2.78)] for external in-migrants compared to residents; there was no statistically significant difference in AIDS mortality between residents and out-migrants, [aOR = 1.25, P = 0.533, 95% CI (0.62–2.53)]. Independently, females were more likely to die from AIDS than males [aOR = 2.35, P < 0.001, 95% CI (1.79, 3.08)].Conclusion: external in-migrants have a higher risk of dying, especially from HIV related causes, than residents, and in areas with substantial migration this needs to be taken into account in evaluating mortality statistics and planning health care service
Age Patterns of Mortality within Childhood in Sub-Saharan Africa
Full text linkThe age pattern of mortality in sub-Saharan Africa and how it varies across the continent remain poorly understood. The region lacks accurate registration statistics and assumptions about mortality patterns are needed to produce and smooth mortality estimates. These have had to be taken from model life table systems based on non-African data. Birth histories collected in national Demographic and Health Surveys are used to investigate age patterns of mortality in childhood in the sub-national regions of 26 countries of continental Sub-Saharan Africa. The majority of populations display a pattern of higher child relative to infant mortality than in any existing model system, including the Princeton "North" models. This reflects the existence of a "hump" of excess mortality in the late post-neonatal period and second year of life in more than three-quarters of sub-national populations. Age patterns of mortality vary markedly within and between countries, though adjacent parts of neighbouring countries sometimes have similar patterns. Particularly extreme relationships between infant and child mortality are most common in the Sahel, while a coastal belt exists adjoining the Indian Ocean with age patterns of mortality within the range of those in the Princeton models. A three-parameter model, which incorporates this "hump", is fitted to the data using Poisson regression and fitted national life tables are produced. Except for the southwest of Africa, no extensive areas exist with homogenous parameter values for the underlying downward slope of mortality with age in childhood and the size of the "hump" respectively. Thus, the scope for construction of "regional" childhood mortality models is limited. Nevertheless, age patterns of mortality in African populations tend to share features that differ from those of historical Western populations. Thus, using the national and regional average life tables in the indirect estimation of under-5 mortality yields more consistent series of estimates than are obtained using existing models
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Adult mortality and its impact on children in two informal settlements in Nairobi, Kenya
Full text linkThis thesis examines the impact of adult deaths on children in two slums in Nairobi city. Over the last two decades, there has been a marked increase in adult mortality in Sub-Saharan Africa. Data on adult mortality in the region are scanty and this makes assessment of its impact on child well-being hard. The thesis analyses data from a longitudinal demographic surveillance system that monitors births, migration, and deaths and identifies causes of death using verbal autopsy. Other data collected include: household characteristics, schooling and health care utilisation. It investigates: i) levels, trends and causes of adult deaths; ii) the impact of adult deaths on children’s household circumstances, and iii) the impact of adult deaths on children’s health and social outcomes. Measures of adult mortality were estimated using life-table and survival analysis techniques. Regression techniques were used to assess impact of adult death on children’s migration, living arrangements, survival, immunisation and schooling. Life expectancy in the two slum populations was low. Adult mortality was higher in women than men. Ethnicity, gender, wealth status were associated with the risk of adult death. Overall, HIV/AIDS was the leading cause of adult death, followed by injuries and tuberculosis. The risk of death from HIV/AIDS was highest in Korogocho slum and the Luo ethnic group. Child mobility in the slums was high. After death of a mother, the risk of child out-migration increased. Death of a father increased average household size while death of a mother resulted in a reduction in household size. Households that experienced adult deaths were more likely to be headed by an older person. Death of a mother, especially from HIV/AIDS, but not that of a father, increased the risk of child death. The risk was highest in the 6 months before and after maternal death. The effect of adult deaths on children’s education depended on slum of residence. While Viwandani children had better educational outcomes overall, death of a mother in Viwandani resulted into poorer schooling outcomes. Interventions aimed at the leading causes of adult deaths need to be scaled up. The results here confirm that adult deaths negatively impact child well-being in this urban setting. Child survival can benefit from scaling up existing interventions, while mitigation of social impacts may require a mix of family and institution-based support for orphaned and vulnerable children
Advances in the Measurement of Adult Mortality from Data on Orphanhood
Full text linkThe premature death of adults is a major, but poorly documented, health problem in developing countries. The inadequacy of registration statistics and difficulty of collecting accurate data directly in surveys mean that indirect methods of analysis, particularly those based on orphanhood, represent an important source of adult mortality estimates. Assessments of the orphanhood method have expressed concern about the robustness of the procedures used to estimate life table indices from orphanhood data, particularly for males, about under-reporting of orphanhood, particularly among children (the ‘adoption effect’), and about the ways that complete life tables are derived from indirect estimates. Investigation of the estimation procedures suggests that they are very robust for female mortality and acceptably so for male mortality. Small increases in accuracy would accrue from use of a regression based method to estimate male mortality, that incorporates a more sophisticated fertility model than the original method. Such a procedure is presented, together with one for female mortality based on consistent assumptions. Existing methods for fitting life tables to indirect estimates are sometimes less satisfactory. An alternative approach is proposed and assessed. In some countries, orphanhood estimates are seriously biased by the adoption effect. Such errors can be reduced by techniques that analyze data on orphanhood in adulthood. Two such methods are developed and tested. The first estimates mortality from period data on orphanhood after age 20; the second uses data on orphanhood since first marriage. The methods are sensitive to age exaggeration, but data on young adults are a promising source of recent estimates of adult mortality. Finally, procedures are presented for analyzing data on orphanhood prior to marriage. In countries where adults report this information accurately, it can be used to measure adult mortality up to 35 years before the data were collected
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