International journal of epidemiology
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No prospective studies have examined the association between social networks and all-cause and cause-specific mortality among middle-aged Japanese. The study of varied populations may contribute to clarifying the robustness of the observed effects of social networks and extend their generalizability. ⋯ This study provides evidence that social networks are an important predictor of mortality risk for middle-aged and elderly Japanese men and women. Lack of participation, for men, and being single and lack of meeting close relatives, for women, were independent risk factors for mortality.
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This paper provides a brief overview to four major types of causal models for health-sciences research: Graphical models (causal diagrams), potential-outcome (counterfactual) models, sufficient-component cause models, and structural-equations models. The paper focuses on the logical connections among the different types of models and on the different strengths of each approach. Graphical models can illustrate qualitative population assumptions and sources of bias not easily seen with other approaches; sufficient-component cause models can illustrate specific hypotheses about mechanisms of action; and potential-outcome and structural-equations models provide a basis for quantitative analysis of effects. The different approaches provide complementary perspectives, and can be employed together to improve causal interpretations of conventional statistical results.
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Multicenter Study
Can clinical risk factors for late stillbirth in West Africa be detected during antenatal care or only during labour?
Recent studies have shown that the most important risk factors for perinatal mortality in developing countries are not detectable during antenatal care but can be observed only shortly before or during labour. Although 60% of perinatal deaths in these countries are stillbirths, few epidemiological studies focus on them. We tested the hypothesis that the risk factors for late stillbirth in West Africa are detectable principally shortly before or during labour. ⋯ The principal risk factors for late stillbirth observed in our study could be detected only in the late antenatal and intrapartum period. These results highlight the potential benefits of partograph use. They need to be confirmed by studies incorporating continuous intrapartum fetal monitoring.