Data on identical and fraternal twins have proven to be an invaluable resource for research on aging because of the ability to utilize the “twin design” in order to (a) control for unobserved endowments – including genetic dispositions and family backgrounds – in behavioral analyses of health outcomes, and (b) conduct behavioral genetic analyses that disentangle genetic, shared environment and non-shared environmental factors. Because of the lack of a large-scale national twin registry covering important agingrelated aspects in old age twins in the United States, most of this research has used twin registries from other countries, including Denmark, Sweden, and Australia. To the extent that U.S. specific institutional settings, such as implied by the U.S. social security system, the health care system, the labor market and many aspects of the U.S. socioeconomic environment, are important determinants of health outcomes, research using non-U.S. based twin data is limited in its ability to inform important questions related to the health determinants and the implications of aging in the United States.
Depression and anxiety (DA) are important dimensions of mental health (MH) with a significant and growing contribution to the global burden of disease. In resource-poor contexts, DA have also been widely recognized as having important implications for demographic events and behaviors such as mortality, migration and divorce, individual productivity, individual/family-level well-being, and overall economic development. Mature adults, defined here as adults aged 45+, are a rapidly-growing subpopulation with key social and economic roles for whom DA and its implications are poorly understood. But there is a lack of longitudinal data on older individuals in SSA that allow us to study the life-course implications of DA and poor MH. To help fill this gap in our knowledge, the specific aims of this project include: (1) Collect new MLSFH data on DA, mortality, marriage and migration in 2016 that, in combination with already existing 2 rounds (2012–13) MLSFH data, will establish a cohort of 1,200+ mature adults aged 45+ for whom this project will obtain the first-ever SSA longitudinal population-based data on depression, anxiety and related key life-course outcomes. (2) Investigate the effects of DA on mortality, migration and demographic behaviors such as divorce/remarriage among mature adults, including the relationship between DA and mortality, the extent to which DA affects family outcomes, such as separation, divorce, remarriage, and analyses of whether migration is an effective coping strategy for mature adults affected by DA. (3) Investigate the patterns, correlates and determinants of DA among mature adults and possible differentials by age, sex, physical health status, socioeconomic status, and family structure.
Two common means of controlling infectious diseases are screening and contact tracing. Contact tracing (CT), also know as “partner notification by provider referral” has been highly effective in controlling diseases like syphilis. While both screening and CT are broadly used to combat the HIV/AIDS epidemic in the US by health departments, governments and funding agencies have favored screening in sub-Saharan countries. This is largely the case because of concerns related to (i) the costs and efficiency of contact tracing in high HIV prevalence settings, and (ii) stigma and discrimination attached to HIV/AIDS. However, the perceived inefficiency of CT comes from mathematical models, which rely heavily on a small set of unrealistic parameters describing sexual behaviors. Recently, the roll-out of antiretroviral treatments (ARV) has also considerably lowered the stigma attached to HIV infection. The main goal of this application is therefore to (re)assess the potential benefits and the feasibility of a CT intervention in a sub-Saharan setting. The specific aims of the project include (a) a modeling of the epidemiological conditions under which CT can be an effective HIV control strategy in sub-Saharan Africa by using innovative and usual data collected as part of the Likoma Network Study in Malawi, and (b) the collection of a cross-sectional surveys of attitudes and beliefs towards CT to assess the acceptability of this intervention among the general population of two rural areas of Malawi (Likoma and Balaka) and the outpatient population of a large urban hospital of Botswana (where researchers from the Penn medical school have long-standing ties).
The goals of this proposed pilot are both substantive and methodological. Substantively, we wish to: One, test the hypothesis that HIV-negative individuals living in a community of high HIV-AIDS prevalence have a greater risk of contracting the disease if their high-sensitivity C-Reactive Protein (hsCRP) is elevated > 3.0mg/L. CRP is a very strong acute-phase protein. During the acute phase of a disease or infection, CRP concentrations rise dramatically. High levels of CRP are also associated with chronic diseases. Inflammation is thought to be a common risk factor for a number of chronic diseases associated with human aging. CRP increases with age, often to levels implicated in arterial degeneration and immunosenescence. In settings with high infectious disease burdens and high mortality, such as Malawi, environmental and life circumstances provide considerable exposure to endemic parasites and associated infections, but few studies have examined the extent to which individuals with high levels of CRP or long exposures to elevated levels of inflammation are at higher risk for contracting HIV than those with low levels of inflammation. Two, evaluate the overall health of some 1000 persons living in the Balaka region in northern Malawi. While members of this community have been previously evaluated for both HIV and STDs, no other health assessments have been undertaken. We seek to evaluate their overall health and well-being using a brief face-to-face interview and conventional biomarkers, such as cholesterol, LDL, HDL, triglycerides (a lipids panel); circulating glucose; urea, albumin, creatinine, total protein, uric acid (collectively a measure of renal function and infection); and HbA1c, a three-month average of blood glucose, a measure of glucose control; and hemoglobin. Methodologically, we wish to test the logistics and feasibility of collecting blood in a developing country with poor health and transportation infrastructures. We request support to administer 1000 Demecal™ biomarker test kits in Balaka, one of three sites of The Malawi Diffusion and Ideational Change Project (MDICP). These test kits require but a single drop of blood and yield values for 15 distinct biomarker assays, including hsCRP. This will be the first test of their use for collecting measures of population health and their adaptability to extreme conditons in tropical zones.
Genetic sequencing allows reconstructing the specific HIV transmission chains through which the virus has diffused and evolved within a population. From the perspective of social science AIDS research, this represents a unique opportunity: such techniques (i) provide objective measurements of the (sexual) connections between members of a population, and (ii) allow new measurements of the HIV-1 diffusion process—the actual transmission of HIV and the diversification of the virus during transmission in sexual networks—whose determinants have largely been understudied. The main aim of this application is therefore to study empirically the social determinants of the transmission and diversification of HIV-1 in a sub-Saharan setting where the prevalence of HIV-1 infection is high. The specific aims of this project include: (1) Create the first large-scale complete-sexual-network study with detailed phylogenetic data in sub-Saharan Africa by complementing the already funded second wave of a unique population-based survey of sexual networks on Likoma Island (Malawi) with genetic sequencing of all identified HIV-1 cases in the study population (N 230). (2) Use the molecular-genotype data to establish chains of HIV infection, and use these reconstructed transmission patterns to (a) assess the validity of sexual network data collected during the survey; and (b) investigate the relationship between reported risk behaviors and actual transmission of HIV-1 along sexual networks. And, (3) investigate the impact of sexual network structures on the rate at which recombinant forms of the virus, dual infections as well as superinfections emerge within a population.
This research investigates mortality differentials in Eastern Europe, a region known for its excessively high adult mortality. It employs a unique longitudinal data set covering the entire population of Bulgaria from the census of 1992 until 1998. It focuses on differences in mortality between Muslims, a large and disadvantaged minority group, and non-Muslims. Virtually nothing is known about the health conditions of Muslims in Europe. Preliminary tabulations suggest that Muslims in Bulgaria have adult mortality levels that are below the national average despite their severe social and economic disadvantages. Hypotheses are developed that attribute this puzzle, similar to the "Hispanic paradox" in the United States, to life-style factors and to social relations. The detailed information available on causes of death will be instrumental in distinguishing the factors involved. A dramatic economic downturn during the period under study will also help to identify factors affecting mortality. Non-parametric hazards models will be employed to test hypotheses. The research should help to identify reasons for the very high and rising mortality in Eastern Europe and to illuminate the health conditions of a large and growing minority population. More generally, it bears upon the relative explanatory power of materialist and social/behavioral approaches to the study of adult health and mortality.
HIV-related stigma has been touted as a barrier to HIV/AIDS prevention and treatment. While various survey instruments and stigma scales have been developed to measure HIV-related stigma in the general population and among persons living with HIV/AIDS (PLWHA), there is no consensus among researchers as to how best to measure stigma or how stigma translates to actual financial discrimination. Also, attitudes expressed in surveys may not represent real behavior. Moreover, even if real behavior is observed, such as that someone exhibited “stigmatizing behavior” towards PLWHA, it is unclear whether this same perpetrator would interact differently with other people without HIV. This pilot study breaks new grounds by using experimental economics games combined with detailed surveys to measure whether people with and without HIV treat each other differently when money is at stake. In this study, we (i) conduct trust, dictator, and ultimatum games (well-known games in the experimental economics field) between persons with and without HIV to examine whether trust, altruism, egalitarian motives, and stigma as revealed in these games differ by HIV status of the participants, and (ii) compare the results from the behavioral economics games with the post-game surveys to construct better measures of HIV-related stigma and to quantify stigma in monetary terms.
The primary aim of the study is to apply existing and develop new models of intergenerational and inter vivos transfers to explain the motivation for such transfers in a high-HIV prevalence country (Malawi) and to investigate whether transfers differ by households that are and are not affected by AIDS. The specific aims are to augment an existing data collection of the Malawi Diffusion and Ideational Change Project (MDICP) in 2004, which is separate from the proposed project, with additional questions on transfers and health to strengthen the value of the MDICP for research on transfers and aging; analyze existing and newly collected data on inter-generational transfers, HIV/AIDS risk perceptions, and bio-marker based HIV-status; assess the impact of AIDS perceptions on transfers utilizing respondents’ subjective beliefs about HIV status and the objective HIV status based on the biomarkers collected in 2004; investigate transfer patterns of persons who died since the 1999 Malawi transfer survey, using information about the cause-of-death based on verbal autopsies; and develop a follow-up survey in 2005 and apply for NIH funding to re-interview the 1999 respondents from the MDICP about patterns of and expectations about transfers with a particular focus on changes due to knowledge about HIV status of the respondent and changes in HIV/AIDS prevalence in the local community.
The structure of sexual networks is an essential determinant of individual’s HIV infection risk and the dynamics of the AIDS epidemic. While mathematical models point to a significant importance of these sexual network structures, virtually no empirical research of this issue using adequate and comprehensive social-science and biomarker data has been conducted in sub-Saharan countries. The specific aims of the proposed study are therefore include (1) the collection of complete sexual and social network data in selected MDICP villages for male and female young adults, using sophisticated ACASI techniques to increase the accurate reporting of sexual network partners; (2) the analysis of the relationships between sexual networks, social networks and HIV prevalence in MDICP villages, including also analyses between the relationship of social and sexual networks; (c) the investigation of the relationship between the social position in sexual and social networks and reported HIV risk infection, AIDS prevention strategies, sexual and marital histories and respondent’s socioeconomic status; and (d) the development tools for the inference of complete network properties based on the local network data that are collected as part of the MDICP. The proposed pilot project is innovative in its study design and substantive contributions, and it promises to strengthen future proposals that build on the Malawi Diffusion and Ideational Change Project.