A Simulation Study of the Conditional Gaussian Diffusion Process Model of Survival Analysis

The recently developed conditional Gaussian diffusion process model is a powerful tool of survival analysis. Its generality not only encompasses the survival models to date but also brings into focus the influence of unobserved variables related to "death" of individuals. Further, that the model makes feasible a unique estimation of the parameters of the underlying unobserved or partially observed process is shown in this paper through a set of simulated data on death times and an unobserved variable. Possibilities of extensive use of the model to areas other than mortality are pointed out

Factors influencing condom use among women in Ghana: an HIV/AIDS perspective

Although in Ghana information on HIV infection and prevention, both in terms of quality and quantity, has increased considerably within the past few years, available literature indicates that behaviour change is yet to correspond with the amount of information and education provided. The objective of this study is to examine factors that influence condom use among women in Ghana in the context of HIV/AIDS prevalence. Data for this study are from the 2003 Ghana Demographic and Health Surveys (GDHS) and the study population (N=5 691) was analysed using logistic regression with the Health Belief Model (HBM) as an explanatory tool. The outcome variable for this study is condom use during last sexual intercourse. The HBM identifies perception of HIV/AIDS risks, awareness of its seriousness, knowledge about prevention, and confidence in condom use as predictors of safe sexual activity. Results show that the proportion of women reporting use of condoms remains tremendously low, in both the rural and urban areas. In the urban areas, only 15% of women reported having sex with condom during their last intercourse, whereas in the rural areas the proportion is even lower (10%). However, multivariate analyses based on the HBM components show that speaking with a partner about how to avoid AIDS (Odds Ratio = 1.63) and perceived benefits of using condoms (Odds Ratio = 1.54) are notable factors that predict condom use. Overall, the study points out that with the exception of perceived severity, the HBM can be applied to understand condom use among the study population. It will be important to emphasise all components of the HBM and empower women with condom negotiation skills.Keywords: Health Belief Model (HBM), HIV/AIDS, condom use, Ghana.Au Ghana, bien que l´information sur la prévention et l´infection VIH est considérablement augmentée au cours des dernières années, aussi bien en qualité qu’en quantité, les publications récentes indiquent que les changements de comportement ne sont pas encore liés à la quantité d’information et à l’éducation dispensée. L’objectif de cette étude est d’examiner les facteurs qui influencent l’utilisation du préservatif chez les femmes au Ghana, dans le cadre de la prévalence du VIH/SIDA. Les données de cette étude provenant de l’enquête sur la démographie et la santé de 2003 et du recensement de la population (N=5 691) ont été analysées en utilisant la méthode de régression logistiques avec le ‘Health Belief’ Modèle (HBM) comme outil d’explication. La finalité de cette étude est de connaître le niveau d’utilisation du préservatif durant les derniers rapports sexuels. La méthode HBM détermine le niveau de perception du risque VIH/SIDA et la conscience de sa gravité, connaissance des mesures de prévention et confiance envers le préservatif comme outil de protection de l’activité sexuelle. Les résultats montrent que la proportion de femmes qui dit utiliser le préservatif demeure extrêmement faible, aussi bien au niveau rural qu’urbain. Dans les zones urbaines, seulement 15% des femmes disent avoir utilisé le préservatif durant le dernier rapport. Aussi, en milieu rural cette proportion est encore plus faible (10%). Quoi qu’il en soit, les multiples analyses basées sur la méthode HBM montrent que parler avec son partenaire sur comment éviter le SIDA (Odds Ratio = 1.63) et des avantages perçus de l’utilisation du préservatif (Odds Ratio = 1.54) sont les facteurs clés qui poussent à l’utilisation du préservatif. En général, l’étude révèle qu’en dehors de sa perception de sévérité, le HBM peut être utilisé pour comprendre l’utilisation du préservatif au sein d’une population. Il est important de souligner tous les aspects de la méthode HBM et en particulier le pouvoir des femmes dans la négociation pour l’utilisation du préservatif

A Multilevel Measurement Model of Social Cohesion

In spite of its currency both in academic research and political rhetoric, there are numerous attempts to define and conceptualize the social cohesion concept but there has been paid little attention to provide a rigorous and empirically tested definition. There are even fewer studies that address social cohesion in a framework of cross-cultural validation of the indicators testing the equivalence of the factorial structure across countries. Finally, as far as we know there is no study that attempt to provide an empirically tested multilevel definition of social cohesion specifying a Multilevel Structural Equation Model. This study aims to cover this gap. First, we provide a theoretical construct of social cohesion taking into account not only its multidimensionality but also its multilevel structure. In the second step, to test the validity of this theoretical construct, we perform a multilevel confirmatory factor analysis in order to verify if the conceptual structure suggested in first step holds. In addition, we test the cross-level structural equivalence and the measurement invariance of the model in order to verify if the same multilevel model of social cohesion holds across the 29 countries analysed. In the final step, we specify a second-order multilevel CFA model in order to identify the existence of a general factor that can be called “social cohesion” operating in society that accounts for the surface phenomena that we observe