Aging of a giant: a stochastic population forecast for China, 2001-2050

This paper presents a stochastic population forecast for China with a special emphasis on population aging. Stochastic forecasting methods have the advantage of producing a projection of the future population including a probabilistic prediction interval. The socalled scaled model for error was used to quantify the uncertainty attached to the population predictions in this study. Data scarcity was a major problem in the specification of the expected error of the population forecast. Therefore, the error structures estimated for European countries were employed with some modifications taking the large size and heterogeneity of the Chinese population into account. The stochastic forecast confirms the expectation of extremely rapid population aging during the first half of the 21st century in China. The old age dependency ratio (OADR) will increase with certainty. By mid-century, with 80% probability, the OADR will lie between 0.41 and 0.56, with the median of the predictive distribution being 0.48, nearly five-fold its current value of 0.1. In particular, the oldest-old population will grow faster than any other age group. This development has major implications for China: to smoothly adjust current birth control policies to less restrictive ones, strengthen the family support system, and improve the social security system for the elderly.China

Higher education delays and shortens cognitive impairment. A multistate life table analysis of the US Health and Retirement Study

Improved health may extend or shorten the duration of cognitive impairment by postponing incidence or death. We assess the duration of cognitive impairment in the US Health and Retirement Study (1992–2004) by self reported BMI, smoking and levels of education in men and women and three ethnic groups. We define multistate life tables by the transition rates to cognitive impairment, recovery and death and estimate Cox proportional hazard ratios for the studied determinants. 95% confidence intervals are obtained by bootstrapping. 55 year old white men and women expect to live 25.4 and 30.0 years, of which 1.7 [95% confidence intervals 1.5; 1.9] years and 2.7 [2.4; 2.9] years with cognitive impairment. Both black men and women live 3.7 [2.9; 4.5] years longer with cognitive impairment than whites, Hispanic men and women 3.2 [1.9; 4.6] and 5.8 [4.2; 7.5] years. BMI makes no difference. Smoking decreases the duration of cognitive impairment with 0.8 [0.4; 1.3] years by high mortality. Highly educated men and women live longer, but 1.6 years [1.1; 2.2] and 1.9 years [1.6; 2.6] shorter with cognitive impairment than lowly educated men and women. The effect of education is more pronounced among ethnic minorities. Higher life expectancy goes together with a longer period of cognitive impairment, but not for higher levels of education: that extends life in good cognitive health but shortens the period of cognitive impairment. The increased duration of cognitive impairment in minority ethnic groups needs further study, also in Europe

The effect of risk factors on disability : a multistate analysis of the U.S. health and retirement study

In de 20ste eeuw is de levensverwachting aanzienlijk toegenomen en de laatste decennia is deze winst vooral te danken aan lagere sterfte op hoge leeftijd. Dit roept de vraag op of de verbetering van de gezondheid alleen sterfte of ook fysieke en cognitieve beperkingen uitstelt. Met andere woorden: met toenemende levensverwachting, met hoeveel neemt het aantal jaren met beperkingen toe? Dit proefschrift bestudeert het effect van Body Mass Index (BMI), roken en opleiding op de duur van fysieke en cognitieve beperkingen. We passen Cox Proportional Hazard modellen toe, multistate sterftetafels, microsimulatie en gevoeligheidsanalyse van het multistate model. De resultaten van de Health and Retirement Study laten zien dat BMI, roken en opleidingsniveau een totaal verschillend effect hebben op de duur van fysieke en cognitieve beperkingen. Een hoge BMI verkort het leven niet, maar voegt jaren toe met fysieke beperkingen. Rokers leven korter, ook korter met beperkingen. Een hoge opleiding combineert het beste van twee werelden: Hogeropgeleiden hebben een hoge levensverwachting, maar leven niet zo lang met (cognitieve) beperkingen.

Fat chance! A closer look at the effect of overweight on mortality

The number of people with overweight or obesity is increasing the world over.The Netherlands is no exception:In the past 20 years the percentage of obese people has practically doubled to about 12 percent. Our present-day food-orientated consumer society with an abundance of calorie-rich food and a structural lack of physical exercise is often given the blame.Obesity raises health risks,and until the 1990s overweight and obesity were thought to be related to an increased mortality risk.Studies at the time indicated that adiposity was very damaging for one’s health and that it claimed as many years of life as smoking.More recent research results from the late 1990s show,however,that overweight at an advanced age does not increase the risk of mortality.In fact,men older than 55 who are overweight live 1.5 years longer than normal-weight men

Dementie: keerzijde van een lang leven

Voor veel mensen is dementie één van de belangrijkste schrikbeelden van veroudering. De kans om dement te worden neemt op hoge leeftijd sterk toe. Dit betekent dat, hoe ouder we met elkaar worden, hoe meer mensen worden geconfronteerd met dementie. Een demografisch epidemiologische studie bestudeert de verwachte levensduur met dementie voor verschillende groepen