On damage accumulation and biological aging

If biological aging is understood as some process of damage accumulation, it does not necessarily lead to increasing mortality rate. Within the framework of suggested models and relevant examples we show that even for the monotonically increasing degradation, the mortality rate can, at least, ultimately decrease. Aging properties of systems with imperfect repair are also studied. It is shown that for some models of imperfect repair the corresponding age process is monotone and stable. This means that as t→∞$t\to \infty$, degradation slows down, which results in the mortality rate deceleration and its possible convergence to a constant.     

Confidence estimation via the parametric bootstrap in logistic joinpoint regression

We consider asymptotic properties of the maximum likelihood and related estimators in a clustered logistic joinpoint model with an unknown joinpoint. Sufficient conditions are given for the consistency of confidence bounds produced by the parametric bootstrap; one of the conditions required is that the true location of the joinpoint is not at one of the observation times. A simulation study is presented to illustrate the lack of consistency of the bootstrap confidence bounds when the joinpoint is an observation time. A removal algorithm is presented which corrects this problem, but at the price of an increased mean square error. Finally, the methods are applied to data on yearly cancer mortality in the US for individuals age 65 and over.     

Determinants of infant and child mortality in Kenya: an analysis controlling for frailty effects

In this paper, Weibull unobserved heterogeneity (frailty) survival models are utilized to analyze the determinants of infant and child mortality in Kenya. The results of these models are compared to those of standard Weibull survival models. The study particularly examines the extent to which child survival risks continue to vary net of observed factors and the extent to which nonfrailty models are biased due to the violation of the statistical assumption of independence. The data came from the 1998 Kenya Demographic and Health Survey. The results of the standard Weibull survival models clearly show that biodemographic factors are more important in explaining infant mortality, while socioeconomic, sociocultural and hygienic factors are more important in explaining child mortality. Frailty effects are substantial and highly significant both in infancy and in childhood, but the conclusions remain the same as in the nonfrailty models.     

广东人口死亡状况研究

本文利用 2 0 0 0年第五次全国人口普查资料 ,全面分析广东人口死亡水平的发展变化、地区和城乡差别、性别与年龄差异以及影响因素。     

The influence of cohort effects on mortality trends in India

The inferences drawn from this study are as follows: The stagnation/ increase in mortality rates of adult ages in the recent years in India as well as for the major states may be attributed to food shortages and price hikes experienced in the country during 1960–74. In other words, all those who were adults during 1980s had experienced the crisis of hunger due to nonavailability of food as well as entitlement failure during their childhood. These persons would have had higher risk of dying in their life time and that may be one of the main reasons for the stagnation or increase in adult mortality in India and in most of the states. The findings of the study suggest that, the economic crisis experienced in India during the late eighties, may decrease the survival chances of those born during this period in their future life time. However, successful containment of increase in food prices during the period of crisis would be helpful in protecting the entitlement of vulnerable groups. The policy implication of the study is that it is essential to control the prices of food during the time of food shortages and or economic crisis and even in the period when food is available, measures should be undertaken to evolve efficient distribution system ensuring the supply of food to those vulnerable groups, who were unlucky to be born or were in infancy during the period of economic crisis. Thus, essentially this is a study in interaction of economic factors and demographic trends in an economy where large segments of the population are periodically subject to heightened food insecurities, compression of real wages and entitlement failures.     

Recent health trends in the Native American population

This paper reviews the changes in the health status of Native Americans since the mid-1950s, how the disease pattern differs from non-Natives, and regional differences within the Native American population. Despite some limitations, data from the Indian Health Service indicate that substantial decline in the infant mortality rate and mortality from such infectious diseases as tuberculosis and gastroenteritis has occurred. With the exception of cardiovascular diseases and cancer, the risk of death from most causes are higher among Native Americans than the total US population. Geographic variation in disease rates can be demonstrated, most notable in diabetes. The unique pattern of diseases among Native Americans reflect the interaction of environmental and genetic factors. Genetic susceptibility plays a significant role in some diseases, such as diabetes, while for others, the generally lower socioeconomic status, higher prevalence of certain health risk behaviors and lower utilization of preventive services in the Native American population are important determinants.     

流行病学转变--人口变化的流行病学理论的形成和发展

本文主要综述了流行病学转变理论的形成和发展,重点介绍了流行病学转变理论的四个基本概念,流行病学转变与人口和社会变化之间的关系,流行病学转变的机理,流行病学转变的影响因素及其在转变中的作用.     

Extreme Temperature and Mortality by Educational Attainment in Spain, 2012–2018

Extreme temperatures are a threat to public health, increasing mortality in the affected population. Moreover, there is substantial research showing how age and gender shape vulnerabilities to this environmental risk. However, there is only limited knowledge on how socioeconomic status (SES), operationalized using educational attainment, stratifies the effect of extreme temperatures on mortality. Here, we address this link using Poisson regression and administrative data from 2012 to 2018 for 50 Spanish Provinces on individuals aged above 65 matched with meteorological data provided by the E-OBS dataset. In line with previous studies, results show that hot and cold days increase mortality. Results on the interaction between SES and extreme temperatures show a positive and significant effect of exposure to heat and cold for individuals with medium and low SES level. Conversely, for high SES individuals we do not find evidence of a robust association with heat or cold. We further investigate how the local climate moderates these associations. A warmer climate increases risks with exposures to low temperatures and vice versa for hot temperatures in the pooled sample. Moreover, we observe that results are mostly driven by low SES individuals being particularly vulnerable to heat in colder climates and cold in warmer climates. In conclusion, results highlight how educational attainment stratifies the effect of extreme temperatures and the relevance of the local climate in shaping risks of low SES individuals aged above 65.     

中国人口增长:过去的演变和未来的预测

本文讨论了过去４５年中国人口生育率和死亡率的变化趋势,据此趋势作出了三个生育率和死亡率的假设,由此预测了未来５０ 年中国人口的增长。最后讨论了两个重要的人口增长的影响因素：就业和人口老龄化     

中国老年人口死亡变动状况之研究

通过对中国各地区不同的人口老龄化程度、死亡中老年人口比例与该地区老年人口比例关系、老年人死亡人口的性差异、老年人口死亡率随时间变化的趋势的研究,并同比较发达的国家作了比较,得出了一些带有规律性的结论