Dementia in Germany: past trends and future developments
281 pages. Rostock, Universität Rostock (2011)
The aging of the population worldwide is an issue that is attracting an increasing amount of attention. In the more developed regions, including Europe and the United States, every fifth person was older than 60 years in 2000. By 2050, this figure will jump to 35%. Worldwide the percentage of people age 60 and above is also rising, and is expected to grow from 10% in 2000 to 21% in 2050 (United Nations, 2005).
The changes in the population structure will lead to far-reaching rearrangements in societies and political systems, as countries adjust to having a higher share of older people. Disability and care need play an important role in an aging population. How many people will be in need of care, and who will care for them?
Dementia and cognitive impairments afflict a high proportion of elderly people who are in need of care and who suffer from chronic illnesses. In past centuries, relatively few people reached the ages at which dementia typically occurs; thus, for a long time, dementia was regarded as a natural consequence of aging. The aging of the population has led to a greater focus on the syndrome: as the number of elderly people has grown, the number of demented people has increased as well.
Today mental and behavioral disorders represent four of the 10 leading causes of disability worldwide, and they are estimated to account for 12% of the global burden of disease (World Health Organization, 2001). European and Northern American studies show that about one-fourth of the population above age 65 suffers from a mental health problem. About 6% to 10% have severe dementia and severe functional psychoses (Bickel, 2003; Hendrie, 1998). For people above age 60, dementia accounts for 11.2% of all years lived with disability.
The number of sufferers from dementia in 2009 is estimated to about 34 million people worldwide (Wimo et al., 2010), an increase of 5 million people within only 5 years (Wimo et al., 2007). About 46% of the demented people live in Asia, 30% in Europe and 12% in North America (Wimo et al., 2003). Estimates of the numbers of dementia patients in Europe for the year 2000 range from 4.624 million Europeans (EU25) between ages 30 and 99 (Eurostat, 2003) to 7.1 million (European Commission, 2004). Due to their higher mean age, more women are affected: 2.9 million women, compared with 1.7 million men (taking the numbers from Eurostat (2003) into account). For the year 2006, the European Community Concerted Action on the Epidemiology and Prevention of Dementia (EURODEM) group (Alzheimer Europe, 2006) estimated that there were about 5.37 million dementia cases. In Germany, about one million people live with dementia (Bickel, 2008; Hallauer, 2002).
The quantification of dementia is very diffcult, as the conflicting findings for Europe make clear. Different definitions and measurement methodologies lead to diverging results. A rising awareness might further influence the number of affected cases, because the syndrome is diagnosed earlier and more frequently. Increasing attention is now devoted to the topic, as can be seen from the larger number of journals, programs and initiatives dealing with the topic, and the growing number of studies analyzing the epidemiology of dementia, the prevalence and incidence of dementing illnesses, and the risk factors of the syndrome (Fratiglioni et al., 1999; Larson et al., 1992). Still, the knowledge about dementia is in the early stages.
The dissertation is structured into seven chapters. Following the introduction in the first chapter, the second chapter provides a literature overview of dementia, including its prevalence, incidence rates, trends and determinants; as well as of the efforts undertaken to medicate and prevent the syndrome. In a systematic literature review, we look at the change in dementia prevalence or incidence over time. The main research question is derived from this information: How is the number of people with dementia in Germany going to develop taking past trends and determinants into account?
In the following chapters, the results of empirical analyses for Germany are shown. Chapter 3 presents results on dementia which are calculated with a unique dataset from the German sickness funds, which includes more than 2.3 million people. This is the first time information on prevalence and incidence rates for Germany are calculated with a German dataset for the entire country. Due to its large sample size, results can not only be separated by age, but also by gender and region. Finally, the co-morbidity of people with prevalent and incident dementia is examined in chapter 4.
In chapter 5, data from the Survey of Health, Ageing and Retirement in Europe (SHARE) are used to analyze severe cognitive impairment. The dataset provides a variety of socio-demographic, lifestyle and physical and mental health variables which help to explain more completely the influencing determinants. Furthermore, the longitudinal design of the data allows for the analysis of trends of severe cognitive impairment.
The results presented in these chapters provide the basis for different projection scenarios of the future number of people with dementia in Germany, which are presented in chapter 6. Projections are always uncertain. On the one hand, all the people who will turn 60 by the year 2050 – the group of people most likely to contract the disease – have already been born; but, on the other hand, there are more uncertain factors, such as the development of life expectancy and of dementia prevalence and incidence. So far for Germany, only constant prevalence projections exist. Ziegler and Doblhammer (2010) and Doblhammer et al. (2009) calculated prevalence projections with decreasing prevalences. Here, multi-state projections using incidence rates and different death rates for the demented and not-demented population will be shown.
Dementia is one of the most costly diseases because of the large amount of care sufferers require. Chapter 7 deals with the current costs, and shows why it is so difficult to estimate the true costs of the disease. Furthermore, cost projections until 2050 are shown.
Finally, a conclusion based on the results is provided in chapter 8. What will the future of the aging German population with dementia look like?