Accounting for recent trends in the prevalence of diarrhoea in the Democratic Republic of Congo (DRC) : results from consecutive cross-sectional surveys

Objectives: To analyse trends in diarrhoea prevalence by maternal education, access to clean water and improved sanitation, household wealth index; to identify the sources of variation and assess contribution of changes in socioeconomic characteristics in the Democratic Republic of Congo (DRC). Design: Consecutive cross-sectional surveys. Setting: DRC. Participants: The databases contain information on 9748 children from the 2001 Multiple Indicators Cluster Survey and 7987 children from the 2007 Demographic and Health Survey. Interventions: N/A. Primary and secondary outcome measures Whether the child had diarrhoea 14 days preceding the survey. Results: The overall prevalence of diarrhoea decreased by 26 percent (from 22.1% in 2001 to 16.4% in 2007). Findings from the three complementary statistical methods are consistent and confirm a significant decrease in diarrhoea regardless of socioeconomic characteristics. Changes in behaviour and/or in public health policy seem to be the likely main source of the change. There were no significant changes in diarrhoea prevalence associated with variation of the population structure. It is worth mentioning that the decrease in diarrhoea prevalence is in contrast to the generalised poor living conditions of the population. Therefore, it is difficult to ascertain whether the decline in diarrhoea prevalence was due to real improvement in public-health policy or to data quality issues. Conclusions: The decline of diarrhoea prevalence in our study need to be further investigated by conducting district-based or provincial-based studies to validate findings from household surveys such as Demographic and Health Surveys and Multiple Indicators Cluster Survey taking into account the current context of the country: ongoing conflict, poor socioeconomic and poor health infrastructure. However, improvement in living conditions such as access to clean water and improved sanitation will contribute to accelerate the reduction of diarrhoea prevalence as well as reduction of child mortality

Childhood mortality in sub-Saharan Africa : cross-sectional insight into small-scale geographical inequalities from Census data

Objectives To estimate and quantify childhood mortality, its spatial correlates and the impact of potential correlates using recent census data from three sub-Saharan African countries (Rwanda, Senegal and Uganda), where evidence is lacking. Design Cross-sectional. Setting Nation-wide census samples from three African countries participating in the 2010 African Census round. All three countries have conducted recent censuses and have information on mortality of children under 5 years. Participants 111 288 children under the age of 5 years in three countries. Primary and secondary outcome measures Under-five mortality was assessed alongside potential correlates including geographical location (where children live), and environmental, bio-demographic and socioeconomic variables. Results Multivariate analysis indicates that in all three countries the overall risk of child death in the first 5 years of life has decreased in recent years (Rwanda: HR=0.04, 95% CI 0.02 to 0.09; Senegal: HR=0.02 (95% CI 0.02 to 0.05); Uganda: HR=0.011 (95% CI 0.006 to 0.018). In Rwanda, lower deaths were associated with living in urban areas (0.79, 0.73, 0.83), children with living mother (HR=0.16, 95% CI 0.15 to 0.17) or living father (HR=0.38, 95% CI 0.36 to 0.39). Higher death was associated with male children (HR=1.06, 95% CI 1.02 to 1.08) and Christian children (HR=1.14, 95% CI 1.05 to 1.27). Children less than 1 year were associated with higher risk of death compared to older children in the three countries. Also, there were significant spatial variations showing inequalities in children mortality by geographic location. In Uganda, for example, areas of high risk are in the south-west and north-west and Kampala district showed a significantly reduced risk. Conclusions We provide clear evidence of considerable geographical variation of under-five mortality which is unexplained by factors considered in the data. The resulting under-five mortality maps can be used as a practical tool for monitoring progress within countries for the Millennium Development Goal 4 to reduce under-five mortality in half by 2015

Spatial variation of salt intake in Britain and association with socioeconomic status

Objectives: To evaluate spatial effects of variation and social determinants of salt intake in Britain. Design: Cross-sectional survey. Setting: Great Britain. Participants: 2105 white male and female participants, aged 19–64 years, from the British National Diet and Nutrition Survey 2000–2001. Primary outcomes: Participants’ sodium intake measured both with a 7-day dietary record and a 24-h urine collection. By accounting for important linear and non-linear risk factors and spatial effects, the geographical difference and spatial patterns of both dietary sodium intake and 24-h urinary sodium were investigated using Bayesian geo-additive models via Markov Chain Monte Carlo simulations. Results: A significant north–south pattern of sodium intake was found from posterior probability maps after controlling for important sociodemographic factors. Participants living in Scotland had a significantly higher dietary sodium intake and 24-h urinary sodium levels. Significantly higher sodium intake was also found in people with the lowest educational attainment (dietary sodium: coeff. 0.157 (90% credible intervals 0.003, 0.319), urinary sodium: 0.149 (0.024, 0.281)) and in manual occupations (urinary sodium: 0.083 (0.004, 0.160)). These coefficients indicate approximately a 5%, 9% and 4% difference in average sodium intake between socioeconomic groups. Conclusions: People living in Scotland had higher salt intake than those in England and Wales. Measures of low socioeconomic position were associated with higher levels of sodium intake, after allowing for geographic location

Geographic variation of female genital mutilation and legal enforcement in sub-saharan Africa : a case study of Senegal

This paper draws on household data to examine the prevalence of female genital mutilation (FGM) in Senegal and the effectiveness of the country's anti-FGM law in dealing with actual breaches and providing protection to the victims. The 2010-2011 Senegal Demographic Health Survey and Multiple Indicators Cluster Survey (SDHS-MICS) covers 14,228 women and their daughters. Logistic regression was used to investigate the geographic distribution of FGM across regions. For the enforceability of anti-FGM, desk research was used. Overall prevalence among women and daughters was 28.1% and 6.2%, respectively. Significant factors were sociodemographics, ethnicity, and region. This analysis shows both advantages and vulnerabilities of the anti-FGM law in relation to the issue of enforcement. It indicates that the law falls short of offering adequate protection to potential victims. FGM is a cultural and social norm imbedded predominantly in rural settings and as such, drives resistance to jettisoning FGM. Legislation has been one of the driving forces behind the eradication of the practice

Factors associated with female genital mutilation in Burkina Faso and its policy implications

Background: Female genital mutilation (FGM) usually undertaken between the ages of 1-9 years and is widely practised in some part of Africa and by migrants from African countries in other parts of the world. Laws prohibit FGM in almost every country. FGM can cause immediate complications (pain, bleeding and infection) and delayed complications (sexual, obstetric, psychological problems). Several factors have been associated with an increased likelihood of FGM. In Burkina Faso, the prevalence of FGM appears to have increased in recent years. Methods: We investigated social, demographic and economic factors associated with FGM in Burkina Faso using the 2003 Demographic Health Survey (DHS). The DHS is a nationally representative cross-sectional survey (multistage stratified random sampling of households) of women of reproductive age (15-49 years). Associations between potential risk factors and the prevalence of FGM were explored using c2 and t-tests and Mann Whitney U-test as appropriate. Logistic regression modelling was used to investigate social, demographic and economic risk factors associated with FGM. Main outcome measures: i) whether a woman herself had had FGM; ii) whether she had one or more daughters with FGM. Results: Data were available on 12,049 women. Response rates by region were at least 90%. Women interviewed were representative of the underlying populations of the different regions of Burkina Faso. Seventy seven percent (9267) of the women interviewed had had FGM. 7336 women had a daughter of whom 2216 (30.2%) had a daughter with FGM and 334 (4.5%) said that they intended that their daughter should have it. Univariate analysis showed that age, religion, wealth, ethnicity, literacy, years of education, household affluence, region and who had responsibility for health care decisions in the household had (RHCD) were all significantly related to the two outcomes (p < 0.01). Multivariate analysis stratified by religion mainly confirmed these findings, however, education is significantly associated with a reduced likelihood of FGM only for Christian women. Conclusions and Policy implications: Factors associated with FGM are varied and complex. Younger women and those from specific groups and religions are less likely to have had FGM. A higher level of education may be protective for women from certain religions. Policies should capitalize on these findings and religious leaders should be involved in continuing programmes of action

The spatial distribution of health establishments in Nigeria

The crisis in the health sector of Nigerian economy has been very obvious since the last decade. Unfortunately, no appreciable progress has been made in addressing the crisis and ensuring good health for the populace. One of the myriads of problems facing the Nigerian health system is llimited access to health facilities. The distortions in the Nigerian health sector arising from both vertical and horizontal inequalities have negative implications for the health care delivery system and in meeting the health related Millennium Development Goals (MDGs). Since health is wealth, and like a vicious cycle, the crisis in the health sector will depress the economy and thereby causing further widening inequalities in the system. This paper, therefore, examines the spatial distribution of health establishments in Nigeria with a view to ascertaining whether there is any imbalance. Using the 2007 National Bureau of Statistics (NBS) survey of health establishment in Nigeria and the 2006 population census data, spatial statistical techniques were applied to the data. The Geographic Information System (GIS) software was used for data analysis. The results indicate that there are large inequalities in health care provision across the state, relative to the population size. The policy implication of this paper is that any effort aimed at improving the efficiency of the health care delivery system in Nigeria should ensure that health facilities are established relative to the structure of the population

The epidemiology of HIV infection in Zambia

Population surveys of health and fertility are an important source of information about demographic trends and their likely impact on the HIV/AIDS epidemic. In contrast to groups sampled at health facilities they can provide nationally and regionally representative estimates of a range of variables. Data on HIV sero-status were collected in the 2001-2 Zambia Demographic and Health Survey (ZDHS) and made available in a separate data file in which HIV status was linked to a very limited set of demographic variables. We utilized this data set to examine associations between HIV prevalence, gender, age and geographical location. We apply the generalized geo-additive semi-parametric model as an alternative to the common linear model, in the context of analyzing the prevalence of HIV infection. This model enables us to account for spatial auto-correlation, non-linear, location effects on the prevalence of HIV infection at the disaggregated provincial level (9 provinces) and assess temporal and geographical variation in the prevalence of HIV infection, while simultaneously controlling for important risk factors. 54 % of the overall sample of 3950 was female. The overall HIV positivity rate was 565 (14.3%). The mean age at HIV diagnosis for male was 30.3 (SD: 11.2) and 27.7 (SD: 9.3) for female respectively. Lusaka and Copperbelt have the first and second highest prevalence of AIDS/HIV (marginal odds ratios of 3.24 and 2.88 respectively) but when the younger age of the urban population and the spatial auto-correlation was taken into account Lusaka and Copper belt were no longer among the areas with the highest prevalence. Nonlinear effects of age at HIV diagnosis were also discussed and the importance of spatial residual effects and control of confounders on the prevalence of HIV infection. The study was conducted to assess the spatia pattern and the effect of confounding risk factors on AIDS/HIV prevalence and to develop a means of adjusting estimates of AIDS/HIV prevalence on the important risk factors. Controlling for important risk factors such as geographical location (spatial auto-correlation), age structure of the population, gender gave estimates of prevalence that are statistically robust. Researchers should be encouraged to use all available information in the data to account for important risk factors when reporting AIDS/HIV prevalence. Where this is not possible, correction factors should be applied, particularly where estimates of AIDS/HIV prevalence are pooled in systematic reviews. Our maps can be used for policy planning and management of AIDS/HIV in Zambia

Salt intake, stroke, and cardiovascular disease : meta-analysis of prospective studies

Objective: To assess the relation between the level of habitual salt intake and stroke or total cardiovascular disease outcome. Design: Systematic review and meta-analysis of prospective studies published 1966-2008. Data sources: Medline (1966-2008), Embase (from 1988), AMED (from 1985), CINAHL (from 1982), Psychinfo (from 1985), and the Cochrane Library. Review methods: For each study, relative risks and 95% confidence intervals were extracted and pooled with a random effect model, weighting for the inverse of the variance. Heterogeneity, publication bias, subgroup, and meta-regression analyses were performed. Criteria for inclusion were prospective adult population study, assessment of salt intake as baseline exposure, assessment of either stroke or total cardiovascular disease as outcome, follow-up of at least three years, indication of number of participants exposed and number of events across different salt intake categories. Results: There were 19 independent cohort samples from 13 studies, with 177 025 participants (follow-up 3.5-19 years) and over 11 000 vascular events. Higher salt intake was associated with greater risk of stroke (pooled relative risk 1.23, 95% confidence interval 1.06 to 1.43; P=0.007) and cardiovascular disease (1.14, 0.99 to 1.32; P=0.07), with no significant evidence of publication bias. For cardiovascular disease, sensitivity analysis showed that the exclusion of a single study led to a pooled estimate of 1.17 (1.02 to 1.34; P=0.02). The associations observed were greater the larger the difference in sodium intake and the longer the follow-up. Conclusions: High salt intake is associated with significantly increased risk of stroke and total cardiovascular disease. Because of imprecision in measurement of salt intake, these effect sizes are likely to be underestimated. These results support the role of a substantial population reduction in salt intake for the prevention of cardiovascular disease

Household food (in)security and nutritional status of urban poor children aged 6 to 23 months in Kenya

Background Millions of people in low and low middle income countries suffer from extreme hunger and malnutrition. Research on the effect of food insecurity on child nutrition is concentrated in high income settings and has produced mixed results. Moreover, the existing evidence on food security and nutrition in children in low and middle income countries is either cross-sectional and/or is based primarily on rural populations. In this paper, we examine the effect of household food security status and its interaction with household wealth status on stunting among children aged between 6 and 23 months in resource-poor urban setting in Kenya. Methods We use longitudinal data collected between 2006 and 2012 from two informal settlements in Nairobi, Kenya. Mothers and their new-borns were recruited into the study at birth and followed prospectively. The analytical sample comprised 6858 children from 6552 households. Household food security was measured as a latent variable derived from a set of questions capturing the main domains of access, availability and affordability. A composite measure of wealth was calculated using asset ownership and amenities. Nutritional status was measured using Height-for-Age (HFA) z-scores. Children whose HFA z-scores were below −2 standard deviation were categorized as stunted. We used Cox regression to analyse the data. Results The prevalence of stunting was 49 %. The risk of stunting increased by 12 % among children from food insecure households. When the joint effect of food security and wealth status was assessed, the risk of stunting increased significantly by 19 and 22 % among children from moderately food insecure and severely food insecure households and ranked in the middle poor wealth status. Among the poorest and least poor households, food security was not statistically associated with stunting. Conclusion Our results shed light on the joint effect of food security and wealth status on stunting. Study findings underscore the need for social protection policies to reduce the high rates of child malnutrition in the urban informal settlements

Spatial analysis of risk factors for childhood morbidity in Nigeria

Recent Demographic and Health Surveys (DHS) from Sub-Saharan Africa (SSA) indicate a decline in childhood vaccination coverage but a high prevalence of childhood diarrhea, cough, and fever. We used Nigerian DHS data to investigate the impact of geographical factors and other important risk factors on diarrhea, cough, and fever using geoadditive Bayesian semiparametric models. A higher prevalence of childhood diarrhea, cough, and fever is observed in the northern and eastern states, while lower disease prevalence is observed in the western and southern states. In addition, children from mothers with higher levels of education and those from poor households had a significantly lower association with diarrhea; children delivered in hospitals, living in urban areas, or from mothers having received prenatal visits had a significantly lower association with fever. Our maps are a novel and relevant tool to help local governments to improve health-care interventions and achieve Millennium Development Goals (MDG4)