Verbal autopsy interpretation: a comparative analysis of the InterVA model versus physician review in determining causes of death in the Nairobi DSS

<p>Abstract</p> <p>Background</p> <p>Developing countries generally lack complete vital registration systems that can produce cause of death information for health planning in their populations. As an alternative, verbal autopsy (VA) - the process of interviewing family members or caregivers on the circumstances leading to death - is often used by Demographic Surveillance Systems to generate cause of death data. Physician review (PR) is the most common method of interpreting VA, but this method is a time- and resource-intensive process and is liable to produce inconsistent results. The aim of this paper is to explore how a computer-based probabilistic model, InterVA, performs in comparison with PR in interpreting VA data in the Nairobi Urban Health and Demographic Surveillance System (NUHDSS).</p> <p>Methods</p> <p>Between August 2002 and December 2008, a total of 1,823 VA interviews were reviewed by physicians in the NUHDSS. Data on these interviews were entered into the InterVA model for interpretation. Cause-specific mortality fractions were then derived from the cause of death data generated by the physicians and by the model. We then estimated the level of agreement between both methods using Kappa statistics.</p> <p>Results</p> <p>The level of agreement between individual causes of death assigned by both methods was only 35% (κ = 0.27, 95% CI: 0.25 - 0.30). However, the patterns of mortality as determined by both methods showed a high burden of infectious diseases, including HIV/AIDS, tuberculosis, and pneumonia, in the study population. These mortality patterns are consistent with existing knowledge on the burden of disease in underdeveloped communities in Africa.</p> <p>Conclusions</p> <p>The InterVA model showed promising results as a community-level tool for generating cause of death data from VAs. We recommend further refinement to the model, its adaptation to suit local contexts, and its continued validation with more extensive data from different settings.</p

A community-based intervention for primary prevention of cardiovascular diseases in the slums of Nairobi: the SCALE UP study protocol for a prospective quasi-experimental community-based trial

Abstract Background: The burden of cardiovascular disease is rising in sub-Saharan Africa with hypertension being the main risk factor. However, context-specific evidence on effective interventions for primary prevention of cardiovascular diseases in resource-poor settings is limited. This study aims to evaluate the feasibility and cost-effectiveness of one such intervention-the &quot;Sustainable model for cardiovascular health by adjusting lifestyle and treatment with economic perspective in settings of urban poverty&quot;

Determinants for HIV testing and counselling in Nairobi urban informal settlements

BACKGROUND: Counselling and testing is important in HIV prevention and care. Majority of people in sub-Saharan Africa do not know their HIV status and are therefore unable to take steps to prevent infection or take up life prolonging anti-retroviral drugs in time if infected. This study aimed at exploring determinants of HIV testing and counselling in two Nairobi informal settlements. METHODS: Data are derived from a cross-sectional survey nested in an ongoing demographic surveillance system. A total of 3,162 individuals responded to the interview and out of these, 82% provided a blood sample which was tested using rapid test kits. The outcome of interest in this paper was HIV testing status in the past categorised as "never tested"; "client-initiated testing and counselling (CITC)" and provider-initiated testing and counselling (PITC). Multinomial logistic regression was used to identify determinants of HIV testing. RESULTS: Approximately 31% of all respondents had ever been tested for HIV through CITC, 22% through PITC and 42% had never been tested but indicated willingness to test. Overall, 62% of females and 38% of males had ever been tested for HIV. Males were less likely to have had CITC (OR = 0.47; p value < 0.001) and also less likely to have had PITC (OR = 0.16; p value < 0.001) compared to females. Individuals aged 20-24 years were more likely to have had either CITC or PITC compared to the other age groups. The divorced/separated/widowed were more likely (OR = 1.65; p value < 0.01) to have had CITC than their married counterparts, while the never married were less likely to have had either CITC or PITC. HIV positive individuals (OR = 1.60; p value < 0.01) and those who refused testing in the survey (OR = 1.39; p value < 0.05) were more likely to have had CITC compared to their HIV negative counterparts. CONCLUSION: Although the proportion of individuals ever tested in the informal settlements is similar to the national average, it remains low compared to that of Nairobi province especially among men. Key determinants of HIV testing and counselling include; gender, age, education level, HIV status and marital status. These factors need to be considered in efforts aimed at increasing participation in HIV testing

Prevalence, awareness, treatment and control of hypertension among slum dwellers in Nairobi, Kenya.

AIMS: This study aims to assess the prevalence, awareness, treatment, and control of hypertension in two major slums in Nairobi, Kenya. METHODS: We use data from a cross-sectional population-based survey, conducted in 2008-2009, involving a random sample of 5190 (2794 men and 2396 women) adults aged 18 years and older resident in both slums. RESULTS: Overall, the prevalence (weighted by sampling and response rates) of hypertension (SBP ≥140  mmHg and/or DBP ≥90  mmHg and/or antihypertensive medication) was 12.3% (12.7% in women and 12.0% in men). The overall level of awareness (having been previously informed of hypertensive status by a health professional) among hypertensives was 19.5% (30.7% in women and 10.8% in men). About 47% (44.9% in women and 50.9% in men) of those who were aware of being hypertensive reported being on antihypertensive treatment in the 1 year preceding the survey. Among those who reported being on treatment, only 21.5% (14.4% in women and 35.7% in men) had their hypertension controlled to levels below 140/90  mmHg. Hypertension control among all hypertensives was below 3%. CONCLUSION: Our findings suggest that hypertension is common in the slums, but the rates of awareness, treatment, and control are low. However, once people are aware of their hypertension, most seek treatment. This indicates that the best gains in treatment can be made when awareness is raised. Overall, there is urgent need to implement strategies that improve prevention, detection, and access to effective treatment in these neglected populations

Trends in non-communicable disease mortality among adult residents in Nairobi's slums, 2003-2011: applying InterVA-4 to verbal autopsy data

Background: About 80% of deaths from non-communicable diseases (NCDs) occur in developing countries such as Kenya. However, not much is known about the burden of NCDs in slums, which account for about 60% of the residences of the urban population in Kenya. This study examines trends in NCD mortality from two slum settings in Nairobi. Design: We use verbal autopsy data on 1954 deaths among adults aged 35 years and older who were registered in the Nairobi Urban Health and Demographic Surveillance System between 2003 and 2011. InterVA-4, a computer-based program, was used to assign causes of death for each case. Results are presented as annualized cause-specific mortality rates (CSMRs) and cause-specific mortality fractions (CSMFs) by sex. Results: The CSMRs for NCDs did not appear to change significantly over time for both males and females. Among males, cardiovascular diseases (CVDs) and neoplasms were the leading NCDs - contributing CSMFs of 8 and 5%, respectively, on average over time. Among females, CVDs contributed a CSMF of 14% on average over time, while neoplasms contributed 8%. Communicable diseases and related conditions remained the leading causes of death, contributing a CSMF of over 50% on average in males and females over time. Conclusions: Our findings are consistent with the Global Burden of Disease 2010 study which shows that communicable diseases remain the dominant cause of death in Africa, although NCDs were still significant contributors to mortality. We recommend an integrated approach towards disease prevention that focuses on health systems strengthening in resource-limited settings such as slum

Review of policy action for healthy environmentally sustainable food systems in sub-Saharan Africa

This review comes from a themed issue on Sustainable Food systems, edited by Maria J. Darias, Mafaniso Hara, Israel Navarrete and Eric O. VergerInternational audienceMany sub-Saharan African (SSA) countries are experiencing multiple burdens of malnutrition. Rising overweight/obesity coexist alongside persistent burdens of under-nutrition and multiple micronutrient deficiencies. Poverty and social inequity remain key drivers of unhealthy diets and malnutrition. Diets in SSA are increasingly transitioning towards unhealthy (energydense, nutrient-poor and unsafe) and environmentally unsustainable diets. Healthy, sustainable food systems are required to deal with these considerable challenges equitably, so policy action needs to balance the health, environmental and economic dimensions of diets and food systems. We review evidence in recent literature for which policy actions have the best chance of success in SSA by appraising their likely impact, relevance, cost/affordability and feasibility to help guide policymakers and researchers in their development and evaluation

Comprehensive Review of K-Means Clustering Algorithms

This paper presents a comprehensive review of existing techniques of k-means clustering algorithms made at various times. The k-means algorithm is aimed at partitioning objects or points to be analyzed into well separated clusters. There are different algorithms for k-means clustering of objects such as traditional k-means algorithm, standard k-means algorithm, basic k-means algorithm and the conventional k-means algorithm, this are perhaps the most widely used versions of the k-means algorithms. These algorithms uses the Euclidean distance as its metric and minimum distance rule approach by assigning each data points (objects) to its closest centroids

The magnitude of diabetes and its association with obesity in the slums of Nairobi, Kenya: results from a cross-sectional survey

To assess the prevalence, awareness, treatment and control of diabetes and to examine the relationship of obesity with raised blood glucose in the slums of Nairobi, Kenya. We used data from a cross-sectional population-based survey, conducted in 2008-2009, involving a random sample of 5190 (2794 men and 2396 women) adults aged ≥18 years living in two slums - Korogocho and Viwandani - in Nairobi. The prevalence (weighted by sampling and response rates) of diabetes was 4.8% (95%CI 4.0-5.7) in women and 4.0% (95%CI 3.3-4.7) in men. Less than a quarter of those found to have diabetes were aware of their condition among which just over half of men and three-quarters of women reported being on any treatment in the 12 months preceding the survey. Overall, fewer than 5% of all people with diabetes had their blood sugar under control. Obesity and overweight were significantly associated with increased odds (1.7, 95%CI 1.1-2.6) of raised blood glucose only among women while adjusting for important covariates. The prevalence of diabetes in this impoverished population is moderately high, while the levels of awareness, treatment and control are quite low. In this population, obesity is an important risk factor for raised blood glucose particularly among women. Prevention and control strategies that target modifiable risk factors for diabetes and increase access to treatment and control in such disadvantaged settings are urgently neede