Bayesian Hierarchical Spatial Modeling and Mapping of Adult Illiteracy in Kenya

Regional disparity in literacy levels must be addressed if Kenya is to achieve its international goals such as Education for All (EFA) and Millennium Development Goals (MDG). Literacy level in Kenya has been on the rise. However, the 2007 Kenya National Literacy Survey crude rates showed that on average 38.5 per cent (7.8 million) of Kenya’s adult population was illiterate with significant regional and gender variation. Bayesian binary logistic models (with and without CAR spatial and unstructured random effects)  are applied to the Kenya National Adult Literacy Survey (2007) data that was obtained from sampled 18000 households, 4782 in urban and 10914 in rural areas, to investigate spatial variation of illiteracy levels in Kenya. There were 15734 successful interviews that were comprised of 6493 were male and 9241 female The best fitted model was found to be the CAR model with age, sex, disability and awareness of adult literacy programs as the significant explanatory variables. Smoothed map of illiteracy from the best fitted model was then produced together with its corresponding confidence interval maps for regional variation in Kenya, in order to capture visual uncertainty in estimation. These maps can be used by policy makers to identify the pattern and tailor make programs appropriate for each region. Keywords: Illiteracy, Bayesian Hierarchical Models, Spatial modelin

The accelerated failure time regression model under the extended-exponential distribution with survival analysis

In this paper, we propose a parametric accelerated failure time (AFT) hazard-based regression model with the extended alpha-power exponential (EAPE) baseline distribution. The proposed model is called the extended alpha-power exponential-AFT (EAPE-AFT) regression model. We show that the EAPE distribution is closed under the AFT model. The parameters of the proposed EAPE-AFT model have been estimated by using the method of maximum likelihood estimation. An extensive simulation study was also conducted to examine the performance of the estimates under several scenarios based on the shapes of the baseline hazard function. Finally, real-life censored survival data has been used to illustrate the applicability of the proposed model

Low adverse event rates following voluntary medical male circumcision in a high HIV disease burden public sector prevention programme in South Africa.

CAPRISA, 2014.Introduction: The provision of voluntary medical male circumcision (VMMC) services was piloted in three public sector facilities in a high HIV disease burden, low circumcision rate province in South Africa to inform policy and operational guidance for scale-up of the service for HIV prevention. We report on adverse events (AEs) experienced by clients following the circumcision procedure. Methods: Prospective recruitment of HIV-negative males aged 12 and older volunteering to be circumcised at three select public health facilities in KwaZulu-Natal between November 2010 and May 2011. Volunteers underwent standardized medical screening including a physical assessment prior to the surgical procedure being performed. AEs were monitored at three time intervals over a 21-day period post-operatively to determine safety outcomes in this pilot demonstration programme. Results: A total of 602 volunteers participated in this study. The median age of the volunteers was 22 years (range 12-56). Most participants (75.6%) returned for the 48-hour post-operative visit; 51.0% for day seven visit and 26.1% for the 21st day visit. Participants aged 20-24 were most likely to return. The AE rate was 0.2% intra-operatively. The frequency of moderate AEs was 0.7, 0.3 and 0.6% at 2-, 7- and 21-day visits, respectively. The frequency of severe AEs was 0.4, 0.3 and 0.6% at 2-, 7- and 21-day visits, respectively. Swelling and wound infection were the most common AEs with mean appearance duration of seven days. Clients aged between 35 and 56 years presented with most AEs (3.0%). Conclusions: VMMC can be delivered safely at resource-limited settings. The intensive three-visit post-operative review practice may be unfeasible due to high attrition rates over time, particularly amongst older men

Prevalence and risk factors of anaemia among children aged between 6 months and 14 years in Kenya.

Anaemia is one of the significant public health problems among children in the world. Understanding risk factors of anaemia provides more insight to the nature and types of policies that can be put up to fight anaemia. We estimated the prevalence and risk factors of anaemia in a population-based, cross-sectional survey.Blood samples from 11,711 children aged between 6 months and 14 years were collected using a single-use, spring-loaded, sterile lancet to make a finger prick. Anaemia was measured based on haemoglobin concentration level. The generalized linear model framework was used to analyse the data, in which the response variable was either a child was anemic or not anemic.The overall prevalence of anaemia among the children in Kenya was estimated to be 28.8%. Across each band of age within which the definition of anaemia remained constant (0–4, 5–11, and 12–14 years old), the prevalence of anaemia declined with each year of age. [corrected]. The risk of anaemia was significantly higher in male than female children. Mothers with secondary and above education had a protective effect on the risk of anaemia on their children. Malaria diagnosis status of a child was positively associated with risk anaemia.Controlling co-morbidity of malaria and improving maternal knowledge are potential options for reducing the burden of anaemia

Assistance in chronic conflict areas: evidence from South Sudan

People living in context prone to or affected by conflict suffer from many forms of deprivation. The international community plays a crucial role in strengthening the wellbeing of affected populations, including their food security. Unfortunately, quite often people exposed to conflict are not reached by national or international assistance because of targeting, accessibility, and marginalization. This can ultimately translate into a further deterioration of their food security status. This paper combines a geo-referenced household dataset collected in South Sudan in 2017 with the Armed Conflict Location and Events Data (ACLED), including information on conflict events. The collection of a very detailed household questionnaire in areas extensively affected by violence allows the analysis in a country generally unexplored by the empirical literature. We analyze the variation in conflict exposure across different households that live in the same district and we test the link between conflict exposure and humanitarian assistance. We find that those who live in the higher-intensity conflict areas, received less assistance than those less exposed to the conflict. The association is stronger with in kind provision of inputs for agriculture and livestock rather than for direct food assistance. We suggest the presence of social elites and marginalization as a possible explanation. We discuss the advantages of using cash transfers through mobile phones to normatively decided beneficiaries; evidence also supports interventions combining input distribution and markets’ rehabilitation. More evidence is needed on the modalities of delivery of humanitarian assistance in different food crises contexts. Cite this content as: d’Errico, M., Ngesa, O. & Pietrelli, R. 2020. Assistance in chronic conflict areas: evidence from South Sudan. FAO Agricultural Development Economics Working Paper 20-01. Rome, FAO

Estimates of the odds ratio, p-value and corresponding 95% confidence intervals (CI).

<p>Estimates of the odds ratio, p-value and corresponding 95% confidence intervals (CI).</p

Discussion on Generalized Modified Inverse Rayleigh

In this paper, a generalization of the modified inverse Rayleigh distribution called the new exponentiated generalized modified inverse Rayleigh distribution is proposed and studied. Various sub-models of the new distribution were discussed and statistical properties such as the quantile function, moment, moment generating function, Re´nyi entropy, reliability measure and order statistics were derived. The parameters of the new model were estimated using the method of maximum likelihood estimation and simulations were performed to assess the stability of the parameters with regards to the estimation method

Alpha Power Transformed Frechet Distribution

The Fr´echet distribution has several applications in different fields of study and is most commonly used for modeling extreme events. In recent time, modifications of the Fr´echet distribution have been proposed to improve its fit when used for modeling lifetime data. In this paper, a new modification called the alpha power transformed Fr´echet distribution is proposed and studied. The parameters of the model are estimated using maximum-likelihood estimation and simulation studies are performed to investigate the properties of the estimators for the parameters. Applications of the model are demonstrated using two-real data sets. Finally, bivariate and multivariate extensions of the model are proposed using copulas

Exploratory data analysis.

<p>Exploratory data analysis.</p

Spatial modeling of HIV and HSV-2 among women in Kenya with spatially varying coefficients

DOI 10.1186/s12889-016-3022-0Background: Disease mapping has become popular in the field of statistics as a method to explain the spatial distribution of disease outcomes and as a tool to help design targeted intervention strategies. Most of these models however have been implemented with assumptions that may be limiting or altogether lead to less meaningful results and hence interpretations. Some of these assumptions include the linearity, stationarity and normality assumptions. Studies have shown that the linearity assumption is not necessarily true for all covariates. Age for example has been found to have a non-linear relationship with HIV and HSV-2 prevalence. Other studies have made stationarity assumption in that one stimulus e.g. education, provokes the same response in all the regions under study and this is also quite restrictive. Responses to stimuli may vary from region to region due to aspects like culture, preferences and attitudes. Methods: We perform a spatial modeling of HIV and HSV-2 among women in Kenya, while relaxing these assumptions i.e. the linearity assumption by allowing the covariate age to have a non-linear effect on HIV and HSV-2 prevalence using the random walk model of order 2 and the stationarity assumption by allowing the rest of the covariates to vary spatially using the conditional autoregressive model. The women data used in this study were derived from the 2007 Kenya AIDS indicator survey where women aged 15–49 years were surveyed. A full Bayesian approach was used and the models were implemented in R-INLA software. Results: Age was found to have a non-linear relationship with both HIV and HSV-2 prevalence, and the spatially varying coefficient model provided a significantly better fit for HSV-2. Age-at first sex also had a greater effect on HSV-2 prevalence in the Coastal and some parts of North Eastern regions suggesting either early marriages or child prostitution. The effect of education on HIV prevalence among women was more in the North Eastern, Coastal, Southern and parts of Central region. Conclusions: The models introduced in this study enable relaxation of two limiting assumptions in disease mapping. The effects of the covariates on HIV and HSV-2 were found to vary spatially. The effect of education on HSV-2 status for example was lower in North Eastern and parts of the Rift region than most of the other parts of the country. Age was found to have a non-linear effect on HIV and HSV-2 prevalence, a linearity assumption would have led to wrong results and hence interpretations. The findings are relevant in that they can be used in informing tailor made strategies for tackling HIV and HSV-2 in different counties. The methodology used here may also be replicated in other studies with similar data