Errors in reported ages and dates in surveys of adult mortality: A record linkage study in Niakhar (Senegal).

Sibling survival histories are a major source of adult mortality estimates in countries with incomplete death registration. We evaluate age and date reporting errors in sibling histories collected during a validation study in the Niakhar Health and Demographic Surveillance System (Senegal). Participants were randomly assigned to either the Demographic and Health Survey questionnaire or a questionnaire incorporating an event history calendar, recall cues, and increased probing strategies. We linked 60-62 per cent of survey reports of siblings to the reference database using manual and probabilistic approaches. Both questionnaires showed high sensitivity (>96 per cent) and specificity (>97 per cent) in recording siblings' vital status. Respondents underestimated the age of living siblings, and age at and time since death of deceased siblings. These reporting errors introduced downward biases in mortality estimates. The revised questionnaire improved reporting of age of living siblings but not of age at or timing of deaths.

Individual, Community, and Social Network Influences on Beliefs Concerning the Acceptability of Intimate Partner Violence in Rural Senegal.

Intimate partner violence (IPV) is a pressing international public health and human rights concern. Recent scholarship concerning causes of IPV has focused on the potentially critical influence of social learning and influence in interpersonal interaction through social norms. Using sociocentric network data from all individuals aged 16 years and above in a rural Senegalese village surveyed as part of the Niakhar Social Networks and Health Project (n = 1,274), we estimate a series of nested linear probability models to test the association between characteristics of respondents' social networks and residential compounds (including educational attainment, health ideation, socioeconomic status, and religion) and whether respondents are classified as finding IPV acceptable, controlling for individual characteristics. We also test for direct social learning effects, estimating the association between IPV acceptability among network members and co-residents and respondents' own, net of these factors. We find individual, social network, and residential compound factors are all associated with IPV acceptability. On the individual level, these include gender, traditional health ideation, and household agricultural investment. Residential compound-level associations are largely explained in the presence of the individual and network characteristics, except for that concerning educational attainment. We find that network alters' IPV acceptability is strongly positively associated with respondents' own, net of individual and compound-level characteristics. A 10% point higher probability of IPV acceptability in respondents' networks is estimated to be associated with a 4.5% point higher likelihood of respondents being classified as finding IPV acceptable. This research provides compelling evidence that social interaction through networks exerts an important, potentially normative, influence on whether individuals in this population perceive IPV as acceptable or not. It also suggests that interventions targeting individuals most likely to perceive IPV as acceptable may have a multiplier effect, influencing the normative context of others they interact with through their social networks.

A latent class analysis of attitudes concerning the acceptability of intimate partner violence in rural Senegal.

BACKGROUND: Research concerning the causes and consequences of intimate partner violence (IPV), particularly in less developed areas of the world, has become prominent in the last two decades. Although a number of potential causal factors have been investigated the current consensus is that attitudes toward IPV on the individual level, likely representing perceptions of normative behavior, and the normative acceptability of IPV on the aggregate level likely play key roles. Measurement of both is generally approached through either binary indicators of acceptability of any type of IPV or additive composite indexes of multiple indicators. Both strategies imply untested assumptions which potentially have important implications for both research into the causes and consequences of IPV as well as interventions aimed to reduce its prevalence. METHODS: Using survey data from rural Senegal collected in 2014, this analysis estimates latent class measurement models of attitudes concerning the acceptability of IPV. We investigate the dimensional structure of IPV ideation and test the parallel indicator assumption implicit in common measurement strategies, as well as structural and measurement invariance between men and women. RESULTS: We find that a two-class model of the acceptability of IPV in which the conditional probability of class membership is allowed to vary between the sexes is preferred for both men and women. Though the assumption of structural invariance between men and women is supported, measurement invariance and the assumption of parallel indicators (or equivalence of indicators used) are not. CONCLUSIONS: Measurement strategies conventionally used to operationalize the acceptability of IPV, key to modeling perceptions of norms around IPV, are a poor fit to the data used here. Research concerning the measurement characteristics of IPV acceptability is a precondition for adequate investigation of its causes and consequences, as well as for intervention efforts aimed at reducing or eliminating IPV.

The Niakhar Social Networks and Health Project.

This paper presents details of the design and implementation of the Niakhar Social Networks and Health Project (NSNHP), a large, mixed-methods project funded by the U.S. National Institute of General Medical Sciences (NIGMS). By redressing fundamental problems in conventional survey network data collection methods, the project is aimed at improving inferences concerning the association between social network structures and processes and health behaviors and outcomes. Fielded in collaboration with an ongoing demographic and health surveillance system in rural Senegal, the NSNHP includes qualitative data concerning the dimensions of social association and health ideologies and behaviors in the study zone, two panels of a new social network survey, and several supplementary and affiliated data sets. •Longitudinal social network survey linked to pre-existing surveillance data•Addresses fundamental methodological constraints in previous social network data•Enables social network analyses of health beliefs, behaviors, and outcomes.

Social learning, influence, and ethnomedicine: Individual, neighborhood and social network influences on attachment to an ethnomedical cultural model in rural Senegal.

The preference in many parts of the world for ethnomedical therapy over biomedical alternatives has long confounded scholars of medicine and public health. In the anthropological literature cultural and interactional contexts have been identified as fundamental mechanisms shaping adherence to ethnomedical beliefs and health seeking behaviors. In this paper, we examine the association between individual, neighborhood, and social network characteristics and the likelihood of attachment to an ethnomedical cultural model encompassing beliefs about etiology of disease, appropriate therapeutic and preventative measures, and more general beliefs about metaphysics and the efficacy of health systems in a rural population in Eastern Senegal. Using data from a unique social network survey, and supplemented by extensive qualitative research, we model attachment to the ethnomedical model at each of these levels as a function of demographic, economic and ideational characteristics, as well as perceived effectiveness of both biomedical and ethnomedical therapy. Individuals' attachment to the ethnomedical cultural model is found to be strongly associated with characteristics of their neighborhoods, and network alters. Experiences with ethnomedical care among neighbors, and both ethnomedical and biomedical care among network alters, are independently associated with attachment to the ethnomedical model, suggesting an important mechanism for cultural change. At the same time, we identify an independent association between network alters' cultural models and those of respondents, indicative of a direct cultural learning or influence mechanism, modified by the degree of global transitivity, or 'connectedness' of individuals' networks. This evidence supports the long held theoretical position that symbolic systems concerning illness and disease are shared, reproduced, and changed through mechanisms associated with social interaction. This has potentially important implications not only for public health programming, but for the understanding of the reproduction and evolution of cultural systems more generally.

Improving survey data on pregnancy-related deaths in low-and middle-income countries: a validation study in Senegal.

OBJECTIVE: In low- and middle-income countries (LMICs), siblings' survival histories (SSH) are often used to estimate maternal mortality, but SSH data on causes of death at reproductive ages have seldom been validated. We compared the accuracy of two SSH instruments: the standard questionnaire used during the demographic and health surveys (DHS) and the siblings' survival calendar (SSC), a new questionnaire designed to improve survey reports of deaths among women of reproductive ages. METHODS: We recruited 1189 respondents in a SSH survey in Niakhar, Senegal. Mortality records from a health and demographic surveillance system (HDSS) constituted the reference data set. Respondents were randomly assigned to an interview with the DHS or SSC questionnaires. A total of 164 respondents had a sister who died at reproductive ages over the past 15 years before the survey according to the HDSS. RESULTS: The DHS questionnaire led to selective omissions of deaths: DHS respondents were significantly more likely to report their sister's death if she had died of pregnancy-related causes than if she had died of other causes (96.4% vs. 70.9%, P < 0.007). Among reported deaths, both questionnaires had high sensitivity (>90%) in recording pregnancy-related deaths. But the DHS questionnaire had significantly lower specificity than the SSC (79.5% vs. 95.0%, P = 0.015). The DHS questionnaire overestimated the proportion of deaths due to pregnancy-related causes, whereas the SSC yielded unbiased estimates of this parameter. CONCLUSION: Statistical models informed by SSH data collected using the DHS questionnaire might exaggerate maternal mortality in Senegal and similar settings. A new questionnaire, the SSC, could permit better tracking progress towards the reduction in maternal mortality.

Adult non-communicable disease mortality in Africa and Asia: evidence from INDEPTH Health and Demographic Surveillance System sites.

BACKGROUND: Mortality from non-communicable diseases (NCDs) is a major global issue, as other categories of mortality have diminished and life expectancy has increased. The World Health Organization's Member States have called for a 25% reduction in premature NCD mortality by 2025, which can only be achieved by substantial reductions in risk factors and improvements in the management of chronic conditions. A high burden of NCD mortality among much older people, who have survived other hazards, is inevitable. The INDEPTH Network collects detailed individual data within defined Health and Demographic Surveillance sites. By registering deaths and carrying out verbal autopsies to determine cause of death across many such sites, using standardised methods, the Network seeks to generate population-based mortality statistics that are not otherwise available. OBJECTIVE: To describe patterns of adult NCD mortality from INDEPTH Network sites across Africa and Asia, according to the WHO 2012 verbal autopsy (VA) cause categories, with separate consideration of premature (15-64 years) and older (65+ years) NCD mortality. DESIGN: All adult deaths at INDEPTH sites are routinely registered and followed up with VA interviews. For this study, VA archives were transformed into the WHO 2012 VA standard format and processed using the InterVA-4 model to assign cause of death. Routine surveillance data also provide person-time denominators for mortality rates. RESULTS: A total of 80,726 adult (over 15 years) deaths were documented over 7,423,497 person-years of observation. NCDs were attributed as the cause for 35.6% of these deaths. Slightly less than half of adult NCD deaths occurred in the 15-64 age group. Detailed results are presented by age and sex for leading causes of NCD mortality. Per-site rates of NCD mortality were significantly correlated with rates of HIV/AIDS-related mortality. CONCLUSIONS: These findings present important evidence on the distribution of NCD mortality across a wide range of African and Asian settings. This comes against a background of global concern about the burden of NCD mortality, especially among adults aged under 70, and provides an important baseline for future work.

Cause-specific childhood mortality in Africa and Asia: evidence from INDEPTH health and demographic surveillance system sites.

BACKGROUND: Childhood mortality, particularly in the first 5 years of life, is a major global concern and the target of Millennium Development Goal 4. Although the majority of childhood deaths occur in Africa and Asia, these are also the regions where such deaths are least likely to be registered. The INDEPTH Network works to alleviate this problem by collating detailed individual data from defined Health and Demographic Surveillance sites. By registering deaths and carrying out verbal autopsies to determine cause of death across many such sites, using standardised methods, the Network seeks to generate population-based mortality statistics that are not otherwise available. OBJECTIVE: To present a description of cause-specific mortality rates and fractions over the first 15 years of life as documented by INDEPTH Network sites in sub-Saharan Africa and south-east Asia. DESIGN: All childhood deaths at INDEPTH sites are routinely registered and followed up with verbal autopsy (VA) interviews. For this study, VA archives were transformed into the WHO 2012 VA standard format and processed using the InterVA-4 model to assign cause of death. Routine surveillance data also provided person-time denominators for mortality rates. Cause-specific mortality rates and cause-specific mortality fractions are presented according to WHO 2012 VA cause groups for neonatal, infant, 1-4 year and 5-14 year age groups. RESULTS: A total of 28,751 childhood deaths were documented during 4,387,824 person-years over 18 sites. Infant mortality ranged from 11 to 78 per 1,000 live births, with under-5 mortality from 15 to 152 per 1,000 live births. Sites in Vietnam and Kenya accounted for the lowest and highest mortality rates reported. CONCLUSIONS: Many children continue to die from relatively preventable causes, particularly in areas with high rates of malaria and HIV/AIDS. Neonatal mortality persists at relatively high, and perhaps sometimes under-documented, rates. External causes of death are a significant childhood problem in some settings.

Malaria mortality in Africa and Asia: evidence from INDEPTH health and demographic surveillance system sites.

BACKGROUND: Malaria continues to be a major cause of infectious disease mortality in tropical regions. However, deaths from malaria are most often not individually documented, and as a result overall understanding of malaria epidemiology is inadequate. INDEPTH Network members maintain population surveillance in Health and Demographic Surveillance System sites across Africa and Asia, in which individual deaths are followed up with verbal autopsies. OBJECTIVE: To present patterns of malaria mortality determined by verbal autopsy from INDEPTH sites across Africa and Asia, comparing these findings with other relevant information on malaria in the same regions. DESIGN: From a database covering 111,910 deaths over 12,204,043 person-years in 22 sites, in which verbal autopsy data were handled according to the WHO 2012 standard and processed using the InterVA-4 model, over 6,000 deaths were attributed to malaria. The overall period covered was 1992-2012, but two-thirds of the observations related to 2006-2012. These deaths were analysed by site, time period, age group and sex to investigate epidemiological differences in malaria mortality. RESULTS: Rates of malaria mortality varied by 1:10,000 across the sites, with generally low rates in Asia (one site recording no malaria deaths over 0.5 million person-years) and some of the highest rates in West Africa (Nouna, Burkina Faso: 2.47 per 1,000 person-years). Childhood malaria mortality rates were strongly correlated with Malaria Atlas Project estimates of Plasmodium falciparum parasite rates for the same locations. Adult malaria mortality rates, while lower than corresponding childhood rates, were strongly correlated with childhood rates at the site level. CONCLUSIONS: The wide variations observed in malaria mortality, which were nevertheless consistent with various other estimates, suggest that population-based registration of deaths using verbal autopsy is a useful approach to understanding the details of malaria epidemiology.

Pregnancy-related mortality in Africa and Asia: evidence from INDEPTH Health and Demographic Surveillance System sites.

BACKGROUND: Women continue to die in unacceptably large numbers around the world as a result of pregnancy, particularly in sub-Saharan Africa and Asia. Part of the problem is a lack of accurate, population-based information characterising the issues and informing solutions. Population surveillance sites, such as those operated within the INDEPTH Network, have the potential to contribute to bridging the information gaps. OBJECTIVE: To describe patterns of pregnancy-related mortality at INDEPTH Network Health and Demographic Surveillance System sites in sub-Saharan Africa and southeast Asia in terms of maternal mortality ratio (MMR) and cause-specific mortality rates. DESIGN: Data on individual deaths among women of reproductive age (WRA) (15-49) resident in INDEPTH sites were collated into a standardised database using the INDEPTH 2013 population standard, the WHO 2012 verbal autopsy (VA) standard, and the InterVA model for assigning cause of death. RESULTS: These analyses are based on reports from 14 INDEPTH sites, covering 14,198 deaths among WRA over 2,595,605 person-years observed. MMRs varied between 128 and 461 per 100,000 live births, while maternal mortality rates ranged from 0.11 to 0.74 per 1,000 person-years. Detailed rates per cause are tabulated, including analyses of direct maternal, indirect maternal, and incidental pregnancy-related deaths across the 14 sites. CONCLUSIONS: As expected, these findings confirmed unacceptably high continuing levels of maternal mortality. However, they also demonstrate the effectiveness of INDEPTH sites and of the VA methods applied to arrive at measurements of maternal mortality that are essential for planning effective solutions and monitoring programmatic impacts.

HIV/AIDS-related mortality in Africa and Asia: evidence from INDEPTH health and demographic surveillance system sites.

BACKGROUND: As the HIV/AIDS pandemic has evolved over recent decades, Africa has been the most affected region, even though a large proportion of HIV/AIDS deaths have not been documented at the individual level. Systematic application of verbal autopsy (VA) methods in defined populations provides an opportunity to assess the mortality burden of the pandemic from individual data. OBJECTIVE: To present standardised comparisons of HIV/AIDS-related mortality at sites across Africa and Asia, including closely related causes of death such as pulmonary tuberculosis (PTB) and pneumonia. DESIGN: Deaths related to HIV/AIDS were extracted from individual demographic and VA data from 22 INDEPTH sites across Africa and Asia. VA data were standardised to WHO 2012 standard causes of death assigned using the InterVA-4 model. Between-site comparisons of mortality rates were standardised using the INDEPTH 2013 standard population. RESULTS: The dataset covered a total of 10,773 deaths attributed to HIV/AIDS, observed over 12,204,043 person-years. HIV/AIDS-related mortality fractions and mortality rates varied widely across Africa and Asia, with highest burdens in eastern and southern Africa, and lowest burdens in Asia. There was evidence of rapidly declining rates at the sites with the heaviest burdens. HIV/AIDS mortality was also strongly related to PTB mortality. On a country basis, there were strong similarities between HIV/AIDS mortality rates at INDEPTH sites and those derived from modelled estimates. CONCLUSIONS: Measuring HIV/AIDS-related mortality continues to be a challenging issue, all the more so as anti-retroviral treatment programmes alleviate mortality risks. The congruence between these results and other estimates adds plausibility to both approaches. These data, covering some of the highest mortality observed during the pandemic, will be an important baseline for understanding the future decline of HIV/AIDS.

Health & demographic surveillance system profile: Bandafassi Health and Demographic Surveillance System (Bandafassi HDSS), Senegal.

The Bandafassi Health and Demographic Surveillance System (Bandafassi HDSS) is located in south-eastern Senegal, near the borders with Mali and Guinea. The area is 700 km from the national capital, Dakar. The population under surveillance is rural and in 2012 comprised 13 378 inhabitants living in 42 villages. Established in 1970, originally for genetic studies, and initially covering only villages inhabited by one subgroup of the population of the area (the Mandinka), the project was transformed a few years later into a HDSS and then extended to the two other subgroups living in the area: Fula villages in 1975, and Bedik villages in 1980. Data have been collected through annual rounds since the project first began. On each visit, investigators review the composition of all the households, checking the lists of people who were present in each household the previous year and gathering information about births, marriages, migrations and deaths (including their causes) since then. One specific feature of the Bandafassi HDSS is the availability of genealogies.

Improving the quality of adult mortality data collected in demographic surveys: validation study of a new siblings' survival questionnaire in Niakhar, Senegal.

BACKGROUND: In countries with limited vital registration, adult mortality is frequently estimated using siblings' survival histories (SSHs) collected during Demographic and Health Surveys (DHS). These data are affected by reporting errors. We developed a new SSH questionnaire, the siblings' survival calendar (SSC). It incorporates supplementary interviewing techniques to limit omissions of siblings and uses an event history calendar to improve reports of dates and ages. We hypothesized that the SSC would improve the quality of adult mortality data. METHODS AND FINDINGS: We conducted a retrospective validation study among the population of the Niakhar Health and Demographic Surveillance System in Senegal. We randomly assigned men and women aged 15-59 y to an interview with either the DHS questionnaire or the SSC. We compared SSHs collected in each group to prospective data on adult mortality collected in Niakhar. The SSC reduced respondents' tendency to round reports of dates and ages to the nearest multiple of five or ten ("heaping"). The SSC also had higher sensitivity in recording adult female deaths: among respondents whose sister(s) had died at an adult age in the past 15 y, 89.6% reported an adult female death during SSC interviews versus 75.6% in DHS interviews (p = 0.027). The specificity of the SSC was similar to that of the DHS questionnaire, i.e., it did not increase the number of false reports of deaths. However, the SSC did not improve the reporting of adult deaths among the brothers of respondents. Study limitations include sample selectivity, limited external validity, and multiple testing. CONCLUSIONS: The SSC has the potential to collect more accurate SSHs than the questionnaire used in DHS. Further research is needed to assess the effects of the SSC on estimates of adult mortality rates. Additional validation studies should be conducted in different social and epidemiological settings. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN06849961

Profile: the Niakhar Health and Demographic Surveillance System.

The Health and Demographic Surveillance System (HDSS) in Niakhar, a rural area of Senegal, is located 135 km east of Dakar. The HDSS was established in 1962 by the Institut de Recherche pour le Développement (IRD) of Senegal to face the shortcomings of the civil registration system and provide demographic indicators. Some 65 villages in the Niakhar area were followed annually by the HDSS from 1962-1969. The study zone was reduced to 8 villages from 1969-1983, and from then on the HDSS was extended to include 22 other villages, covering a total of 30 villages for a population estimated at 43 000 in January 2012. Thus, 8 villages in the Niakhar area have been under demographic surveillance for almost 50 years and 30 villages for 30 years. Vital events, migrations, marital changes, pregnancies, and immunizations are routinely recorded every 4 months. The HDSS data base also includes epidemiological, economic, and environmental information obtained from specific surveys. Data were collected through annual rounds from 1962 to 1987. The rounds became weekly from 1987-1997, followed by routine visits conducted every 3 months between 1997 and 2007 and every 4 months since then. The data collected in the HDSS are not open to access, but can be fairly shared under conditions of collaboration and endowment.

New malaria-control policies and child mortality in senegal: reaching millennium development goal 4.

BACKGROUND: The Demographic Surveillance System established in 1962 in Niakhar, Senegal, is the oldest in Africa. Here, we analyze trends in overall child mortality, malaria, and other causes of death in Niakhar from the beginning of data collection to 2010. METHODS: After an initial census, demographic data were updated yearly from 1963 through 2010. From 1984, causes of death were determined by the verbal autopsy technique. RESULTS: During 1963-2010, infant and under-5 mortality rates decreased from 223‰ to 18‰ and from 485‰ to 41‰, respectively. The decrease was progressive during the entire observation period, except during 1990-2000, when a plateau and then an increase was observed. Malaria-attributable mortality in under-5 children decreased from 13.5‰ deaths per 1000 children per year during 1992-1999 to 2.2‰ deaths per 1000 children per year in 2010. During this period, all-cause mortality among children aged <5 years decreased by 80%. CONCLUSIONS: Inadequate treatment for chloroquine-resistant malaria and an epidemic of meningitis during the 1990s were the 2 factors that interrupted a continuous decrease in child mortality. Direct and indirect effects of new malaria-control policies, introduced in 2003 and completed during 2006-2008, are likely to have been the key cause of the recent dramatic decrease in child mortality.