STUDY OBJECTIVES To examine if social networks with children, relatives, friends, and confidants predict survival in older Australians over 10 years after controlling for a range of demographic, health, and lifestyle variables. DESIGN Prospective longitudinal cohort study (the Australian longitudinal study of aging) SETTING Adelaide, South Australia. PARTICIPANTS 1477 persons aged 70 year...

In the analysis of competing risk data, the observed effect of a covariate can be obtained via a Fine and Gray sub-distribution hazard ratio. Sometimes, it is also desirable to obtain the virtual effect of a covariate as if the competing risks were non-existent. Under the latent failure time scenario, when the event of interest and the competing risk event are independent, the cause-specific ha...

the purchase of insurance may cause the insureds to increase the costs of insurance companies, compared to their estimation of costs. if after the demand of insurance services, the loss ratio of insurance companies increases because of consumer behavior, moral hazard will be evident. in this paper, after introducing the literature, the presence of moral hazard in iran insurance company is teste...

Based on the increasing property of ratio of average reversed hazard rates of two non-negative random variables a new stochastic order for the sake of comparison of two lifetime distributions is proposed. This stochastic order admits some distinguishing properties. In order to illustrate the obtained results, a semi-parametric model which is called reverse hazard power and a mixture model of pr...

In medical studies, it is often of scientific interest to evaluate the treatment effect via the ratio of cumulative hazards, especially when those hazards may be nonproportional. To deal with nonproportionality in the Cox regression model, investigators usually assume that the treatment effect has some functional form. However, to do so may create a model misspecification problem because it is ...

Background: The hazard ratio has been widely used as an index of effect size in clinical trials for time-to-event data. use the Cox proportional hazards models and other centered is ubiquitous relativity sizes (small, medium, large) discussed accepted when comparing magnitude association continuous categorical data, but not yet outcomes. Methods: We review published ratios, investigate relation...

Uncertainty concerning the measurement error properties of self-reported diet has important implications for the reliability of nutritional epidemiology reports. Biomarkers based on the urinary recovery of expended nutrients can provide an objective measure of short-term nutrient consumption for certain nutrients and, when applied to a subset of a study cohort, can be used to calibrate correspo...