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Epidemiology of dementia – A current overview
Public Health Forum 20 Heft 76 (2012) www.journals.elsevier.de/pubhef
Epidemiology of dementia – A current overview Tobias Luck, Melanie Luppa and Steffi G. Riedel-Heller Dementia is a global public health concern. The 2003 WHO report on Global Burden of Disease estimated that dementia contributed 11.2% of years lived with disability in people aged 60 years and older; more than cardiovascular diseases or cancer (WHO, 2003). A Delphi consensus study on the global prevalence and incidence of dementia estimated 4.6 million new cases every year and an increase in the total number of people affected from 24.3 million in 2001 to 81.1 million by 2040 (Ferri et al., 2005). Dementia rates are highly influenced by age. Pooled data from 11 European population-based studies showed a continuous increase in prevalence from age group 65-69 years (0.8%) to age group 90+ years (28.5%) (Lobo et al., 2000). Pooled data also revealed an increase in incidence with age from 2.4 per 1,000 person-years in age group 65-69 to 70.2 per 1,000 person-years in age group 90+; in women incidence rates continued to escalate whereas in men rates reached a plateau at age 85 (Fratiglioni et al., 2000). Statements concerning the incidence of dementia in the ‘‘very old’’, however, should be made with caution, as estimates are usually based on small numbers of observed cases resulting in large confidence intervals (Riedel-Heller et al., 2001). An increase in the number of dementia cases with age constitutes a big challenge for the healthcare systems of aging societies. This is especially true for Europe which is particularly affected by a demographic trend from high to low mortality and high to low fertility rates in the last few decades. Median age of the population and
proportion of older persons in Europe are already higher than in all other continents and both demographic indicators are still expected to increase (United Nations, 2009). Based on population projections of the United Nations and several meta-analyses, Wancata et al. (2003) estimated an increase in the number of prevalent dementia cases in Europe from 7.1 million in 2000 to about 16.2 million in 2050. At the same time, the ratio of persons in working age to one demented person will significantly decrease (from 69:1 to 21:1) leading to a considerable higher financial and emotional burden carried by the working-age population (Wancata et al., 2003). Care of people with dementia already causes enormous costs: The worldwide annual societal costs of dementia were estimated to be $422 billion in 2009; an increase of 34% within only four years (Wimo et al., 2007, 2010). Costs more than double from mild to severe stages of the disease (Quentin et al., 2010). Across the stages, both professional care and informal care by family or friends constitute the most significant cost components of dementia. A recently published estimation attributed approximately three quarters of the total costs to formal and informal care and only one quarter to medical care (Leicht et al., 2011). Giving this picture, detection of prevention and treatment options for dementia is of utmost importance. So far, there are no therapeutic options currently available for the most common form of dementia, the Alzheimer’s dementia (AD) (Ballard et al., 2011). Symptomatic treatments
might be able to stabilize cognition or to delay cognitive decline for a short period. Model-based calculations for the prevalence of AD in the USA, however, suggest that broad-based interventions delaying the disease onset even modestly could already have a major public health impact at the population level: Based on a projected increase of AD prevalence from 2.3 million cases in 1997 to 8.6 million cases 50 years later, Brookmeyer et al. (1998) calculated that there would be nearly 800,000 fewer prevalent cases in 2047, if interventions could delay onset of the disease by only one year and nearly two million fewer cases, if onset could be delayed by two years. In the absence of effective therapeutic options, a healthy lifestyle in general might be the best option to reduce the individual risk of developing dementia (Peters, 2009). There is robust evidence that cognitive reserve – a combination of education, occupation, and mental activities –, physical activity and exercise, midlife obesity, alcohol consumption, and smoking are important modifiable risk factors (Ballard et al., 2011). Moreover, there is evidence that active and socially integrated lifestyle in late life as well as maintaining a Mediterranean diet (high vegetable, fruit and fish intake) might reduce the risk of dementia and AD (Fratiglioni et al., 2004; Peters, 2009). Proper treatment of medical conditions including vascular diseases like stroke, atherosclerosis, midlife hypercholesterolaemia and hypertension could also reduce the individual risk of developing dementia (Ballard et al., 2011; van der Flier and
11.e1
Public Health Forum 20 Heft 76 (2012) www.journals.elsevier.de/pubhef
Scheltens, 2005; Kidd, 2008; Peters, 2009). The mechanisms that link vascular risk factors to AD, however, are not yet completely clarified (van der Flier and Scheltens, 2005). Most recent research questioned the dichotomy between vascular dementia (VD) and AD and a spectrum between both diseases including a large majority of patients with contributions from both Alzheimer and vascular pathologies is suggested (Viswanathan et al., 2009). Further studies are needed to adequately address this neuropathological issue. Future epidemiological research on dementia in general requires the implementation of further longitudinal studies with long observation periods to measure risk (and protective) factors as early as possible and to account for changes in these factors over time (van der Flier and Scheltens,
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2005). Dementias research might also benefit greatly from further investigation into the nature and outcome of possible pre-stages of dementia like mild cognitive impairment or subjective memory impairment (Jessen et al., 2010; Riedel-Heller et al., 2006). No effort should be spared that could help in reducing the burden of dementia for sufferers, caregivers, and societies as a whole.
is financed by means of the European Union, by the European Regional Development Fund (ERDF) and by means of the Free State of Saxony within the framework of the excellence initiative. Die korrespondierende Autorin erkla¨rt, dass kein Interessenkonflikt vorliegt. Literatur siehe Literatur zum Schwerpunktthema. http://journals.elsevier.de/pubhef/literatur http://dx.doi.org/10.1016/j.phf.2012.06.018
Acknowledgement Tobias Luck was supported in writing the publication by a research fellowship of the German Research Foundation (grant: Lu 1730/1-1). Melanie Luppa is related to the Leipzig Interdisciplinary Research Cluster of Genetic Factors, Clinical Phenotypes and Environment (LIFE Centre, University of Leipzig). LIFE
Prof. Dr. med. Steffi G. Riedel-Heller, MPH University of Leipzig Institute of Social Medicine, Occupational Health and Public Health Philipp-Rosenthal-Str. 55 04103 Leipzig, Germany [email protected]. de
Public Health Forum 20 Heft 76 (2012) www.journals.elsevier.de/pubhef
Summary Dementia is common and one of the most burdensome diseases for sufferers and their relatives; it is also one of the biggest challenges for the healthcare systems of aging societies. Professional nursing care and informal care by family or friends constitute the most significant cost components of dementia. In the absence of effective therapeutic options, a healthy lifestyle might be the best option to reduce the individual risk of developing dementia.
Einleitung Demenzen sind ha¨ufig und mit erheblichen Belastungen fu¨r Betroffene und Angeho¨rige verbunden und stellen zudem eine enorme Herausforderung fu¨r die Gesundheitsversorgung in alternden Gesellschaften dar. Professionelle Pflege und informelle Pflege durch Familie und Freunde verursachen die ho¨chsten Kosten in der Versorgung von Demenzpatienten. Solange effektive Therapiemaßnahmen nicht zur Verfu¨gung stehen, du¨rfte ein generell gesunder Lebensstil die beste Mo¨glichkeit darstellen, das individuelle Demenzrisiko zu reduzieren.
Keywords: dementia = Demenz, Alzheimer’s disease = Morbus Alzheimer, prevalence = Pra¨valenz, incidence = Inzidenz, costs = Kosten
References Ballard C, Gauthier S, Corbett A, Brayne C, Aarsland D, Jones E. Alzheimer’s disease. Lancet 2011;377:1019–31. Review. Brookmeyer R, Gray S, Kawas C. Projections of Alzheimer’s disease in the United States and the public health impact of delaying disease onset. Am J Public Health 1998;88:1337–42. Ferri CP, Prince M, Brayne C, Brodaty H, Fratiglioni L, Ganguli M, et al. Alzheimer’s Disease International. Global prevalence of dementia: a Delphi consensus study. Lancet 2005;366:2112–7. Fratiglioni L, Launer LJ, Andersen K, Breteler MM, Copeland JR, Dartigues JF, et al. Incidence of dementia and major subtypes in Europe: A collaborative study of population-based cohorts. Neurologic Diseases in the Elderly Research Group. Neurology 2000;54:S10–5. Fratiglioni L, Paillard-Borg S, Winblad B. An active and socially integrated lifestyle in late life might protect against dementia. Lancet Neurol 2004;3:343–53. Review. Jessen F, Wiese B, Bachmann C, EifflaenderGorfer S, Haller F, Ko¨lsch H, et al., German Study on Aging, Cognition and Dementia in Primary Care Patients Study Group. Prediction of dementia by subjective memory
impairment: effects of severity and temporal association with cognitive impairment. Arch Gen Psychiatry 2010;67:414–22. Kidd PM. Alzheimer’s disease, amnestic mild cognitive impairment, and age-associated memory impairment: current understanding and progress toward integrative prevention. Altern Med Rev 2008;13:85–115. Review. Leicht H, Heinrich S, Heider D, Bachmann C, Bickel H, van den Bussche H, et al., AgeCoDe study group. Net costs of dementia by disease stage. Acta Psychiatr Scand 2011;124:384–95. Lobo A, Launer LJ, Fratiglioni L, Andersen K, Di Carlo A, Breteler MM, et al. Prevalence of dementia and major subtypes in Europe: A collaborative study of population-based cohorts. Neurologic Diseases in the Elderly Research Group. Neurology 2000;54:S4–9. Peters R. The prevention of dementia. Int J Geriatr Psychiatry 2009;24:452–8. Review. Quentin W, Riedel-Heller SG, Luppa M, Rudolph A, Ko¨nig HH. Cost-of-illness studies of dementia: a systematic review focusing on stage dependency of costs. Acta Psychiatr Scand 2010;121:243–59. Review. Riedel-Heller SG, Busse A, Angermeyer MC. The state of mental health in old-age across the ‘old’ European Union– a systematic review. Acta Psychiatr Scand 2006;113:388–401. Review.
Riedel-Heller SG, Busse A, Aurich C, Matschinger H, Angermeyer MC. Incidence of dementia according to DSM-III-R and ICD10: results of the Leipzig Longitudinal Study of the Aged (LEILA75+), Part 2. Br J Psychiatry 2001; 179:255–60. United Nations, Department of Economic and Social Affairs, Population Division. World Population Prospects: The 2008 Revision, Highlights, Working Paper No. ESA/P/ WP.210. New York: UN, 2009. van der Flier WM, Scheltens P. Epidemiology and risk factors of dementia. J Neurol Neurosurg Psychiatry 2005;76(Suppl. 5):v2– 7. Review. Viswanathan A, Rocca WA, Tzourio C. Vascular risk factors and dementia: how to move forward? Neurology 2009;72:368–74. Review. Wancata J, Musalek M, Alexandrowicz R, Krautgartner M. Number of dementia sufferers in Europe between the years 2000 and 2050. Eur Psychiatry 2003;18:306–13. WHO. World Health Report 2003 – Shaping the future. Geneva: WHO, 2003. Wimo A, Winblad B, Jo¨nsson L. An estimate of the total worldwide societal costs of dementia in 2005. Alzheimers Dement 2007;3:81–91. Wimo A, Winblad B, Jo¨nsson L. The worldwide societal costs of dementia: Estimates for 2009. Alzheimers Dement 2010;6:98–103.
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Epidemiology of dementia – A current overview Tobias Luck, Melanie Luppa and Steffi G. Riedel-Heller Dementia is a global public health concern. The 2003 WHO report on Global Burden of Disease estimated that dementia contributed 11.2% of years lived with disability in people aged 60 years and older; more than cardiovascular diseases or cancer (WHO, 2003). A Delphi consensus study on the global prevalence and incidence of dementia estimated 4.6 million new cases every year and an increase in the total number of people affected from 24.3 million in 2001 to 81.1 million by 2040 (Ferri et al., 2005). Dementia rates are highly influenced by age. Pooled data from 11 European population-based studies showed a continuous increase in prevalence from age group 65-69 years (0.8%) to age group 90+ years (28.5%) (Lobo et al., 2000). Pooled data also revealed an increase in incidence with age from 2.4 per 1,000 person-years in age group 65-69 to 70.2 per 1,000 person-years in age group 90+; in women incidence rates continued to escalate whereas in men rates reached a plateau at age 85 (Fratiglioni et al., 2000). Statements concerning the incidence of dementia in the ‘‘very old’’, however, should be made with caution, as estimates are usually based on small numbers of observed cases resulting in large confidence intervals (Riedel-Heller et al., 2001). An increase in the number of dementia cases with age constitutes a big challenge for the healthcare systems of aging societies. This is especially true for Europe which is particularly affected by a demographic trend from high to low mortality and high to low fertility rates in the last few decades. Median age of the population and
proportion of older persons in Europe are already higher than in all other continents and both demographic indicators are still expected to increase (United Nations, 2009). Based on population projections of the United Nations and several meta-analyses, Wancata et al. (2003) estimated an increase in the number of prevalent dementia cases in Europe from 7.1 million in 2000 to about 16.2 million in 2050. At the same time, the ratio of persons in working age to one demented person will significantly decrease (from 69:1 to 21:1) leading to a considerable higher financial and emotional burden carried by the working-age population (Wancata et al., 2003). Care of people with dementia already causes enormous costs: The worldwide annual societal costs of dementia were estimated to be $422 billion in 2009; an increase of 34% within only four years (Wimo et al., 2007, 2010). Costs more than double from mild to severe stages of the disease (Quentin et al., 2010). Across the stages, both professional care and informal care by family or friends constitute the most significant cost components of dementia. A recently published estimation attributed approximately three quarters of the total costs to formal and informal care and only one quarter to medical care (Leicht et al., 2011). Giving this picture, detection of prevention and treatment options for dementia is of utmost importance. So far, there are no therapeutic options currently available for the most common form of dementia, the Alzheimer’s dementia (AD) (Ballard et al., 2011). Symptomatic treatments
might be able to stabilize cognition or to delay cognitive decline for a short period. Model-based calculations for the prevalence of AD in the USA, however, suggest that broad-based interventions delaying the disease onset even modestly could already have a major public health impact at the population level: Based on a projected increase of AD prevalence from 2.3 million cases in 1997 to 8.6 million cases 50 years later, Brookmeyer et al. (1998) calculated that there would be nearly 800,000 fewer prevalent cases in 2047, if interventions could delay onset of the disease by only one year and nearly two million fewer cases, if onset could be delayed by two years. In the absence of effective therapeutic options, a healthy lifestyle in general might be the best option to reduce the individual risk of developing dementia (Peters, 2009). There is robust evidence that cognitive reserve – a combination of education, occupation, and mental activities –, physical activity and exercise, midlife obesity, alcohol consumption, and smoking are important modifiable risk factors (Ballard et al., 2011). Moreover, there is evidence that active and socially integrated lifestyle in late life as well as maintaining a Mediterranean diet (high vegetable, fruit and fish intake) might reduce the risk of dementia and AD (Fratiglioni et al., 2004; Peters, 2009). Proper treatment of medical conditions including vascular diseases like stroke, atherosclerosis, midlife hypercholesterolaemia and hypertension could also reduce the individual risk of developing dementia (Ballard et al., 2011; van der Flier and
11.e1
Public Health Forum 20 Heft 76 (2012) www.journals.elsevier.de/pubhef
Scheltens, 2005; Kidd, 2008; Peters, 2009). The mechanisms that link vascular risk factors to AD, however, are not yet completely clarified (van der Flier and Scheltens, 2005). Most recent research questioned the dichotomy between vascular dementia (VD) and AD and a spectrum between both diseases including a large majority of patients with contributions from both Alzheimer and vascular pathologies is suggested (Viswanathan et al., 2009). Further studies are needed to adequately address this neuropathological issue. Future epidemiological research on dementia in general requires the implementation of further longitudinal studies with long observation periods to measure risk (and protective) factors as early as possible and to account for changes in these factors over time (van der Flier and Scheltens,
11.e2
2005). Dementias research might also benefit greatly from further investigation into the nature and outcome of possible pre-stages of dementia like mild cognitive impairment or subjective memory impairment (Jessen et al., 2010; Riedel-Heller et al., 2006). No effort should be spared that could help in reducing the burden of dementia for sufferers, caregivers, and societies as a whole.
is financed by means of the European Union, by the European Regional Development Fund (ERDF) and by means of the Free State of Saxony within the framework of the excellence initiative. Die korrespondierende Autorin erkla¨rt, dass kein Interessenkonflikt vorliegt. Literatur siehe Literatur zum Schwerpunktthema. http://journals.elsevier.de/pubhef/literatur http://dx.doi.org/10.1016/j.phf.2012.06.018
Acknowledgement Tobias Luck was supported in writing the publication by a research fellowship of the German Research Foundation (grant: Lu 1730/1-1). Melanie Luppa is related to the Leipzig Interdisciplinary Research Cluster of Genetic Factors, Clinical Phenotypes and Environment (LIFE Centre, University of Leipzig). LIFE
Prof. Dr. med. Steffi G. Riedel-Heller, MPH University of Leipzig Institute of Social Medicine, Occupational Health and Public Health Philipp-Rosenthal-Str. 55 04103 Leipzig, Germany [email protected]. de
Public Health Forum 20 Heft 76 (2012) www.journals.elsevier.de/pubhef
Summary Dementia is common and one of the most burdensome diseases for sufferers and their relatives; it is also one of the biggest challenges for the healthcare systems of aging societies. Professional nursing care and informal care by family or friends constitute the most significant cost components of dementia. In the absence of effective therapeutic options, a healthy lifestyle might be the best option to reduce the individual risk of developing dementia.
Einleitung Demenzen sind ha¨ufig und mit erheblichen Belastungen fu¨r Betroffene und Angeho¨rige verbunden und stellen zudem eine enorme Herausforderung fu¨r die Gesundheitsversorgung in alternden Gesellschaften dar. Professionelle Pflege und informelle Pflege durch Familie und Freunde verursachen die ho¨chsten Kosten in der Versorgung von Demenzpatienten. Solange effektive Therapiemaßnahmen nicht zur Verfu¨gung stehen, du¨rfte ein generell gesunder Lebensstil die beste Mo¨glichkeit darstellen, das individuelle Demenzrisiko zu reduzieren.
Keywords: dementia = Demenz, Alzheimer’s disease = Morbus Alzheimer, prevalence = Pra¨valenz, incidence = Inzidenz, costs = Kosten
References Ballard C, Gauthier S, Corbett A, Brayne C, Aarsland D, Jones E. Alzheimer’s disease. Lancet 2011;377:1019–31. Review. Brookmeyer R, Gray S, Kawas C. Projections of Alzheimer’s disease in the United States and the public health impact of delaying disease onset. Am J Public Health 1998;88:1337–42. Ferri CP, Prince M, Brayne C, Brodaty H, Fratiglioni L, Ganguli M, et al. Alzheimer’s Disease International. Global prevalence of dementia: a Delphi consensus study. Lancet 2005;366:2112–7. Fratiglioni L, Launer LJ, Andersen K, Breteler MM, Copeland JR, Dartigues JF, et al. Incidence of dementia and major subtypes in Europe: A collaborative study of population-based cohorts. Neurologic Diseases in the Elderly Research Group. Neurology 2000;54:S10–5. Fratiglioni L, Paillard-Borg S, Winblad B. An active and socially integrated lifestyle in late life might protect against dementia. Lancet Neurol 2004;3:343–53. Review. Jessen F, Wiese B, Bachmann C, EifflaenderGorfer S, Haller F, Ko¨lsch H, et al., German Study on Aging, Cognition and Dementia in Primary Care Patients Study Group. Prediction of dementia by subjective memory
impairment: effects of severity and temporal association with cognitive impairment. Arch Gen Psychiatry 2010;67:414–22. Kidd PM. Alzheimer’s disease, amnestic mild cognitive impairment, and age-associated memory impairment: current understanding and progress toward integrative prevention. Altern Med Rev 2008;13:85–115. Review. Leicht H, Heinrich S, Heider D, Bachmann C, Bickel H, van den Bussche H, et al., AgeCoDe study group. Net costs of dementia by disease stage. Acta Psychiatr Scand 2011;124:384–95. Lobo A, Launer LJ, Fratiglioni L, Andersen K, Di Carlo A, Breteler MM, et al. Prevalence of dementia and major subtypes in Europe: A collaborative study of population-based cohorts. Neurologic Diseases in the Elderly Research Group. Neurology 2000;54:S4–9. Peters R. The prevention of dementia. Int J Geriatr Psychiatry 2009;24:452–8. Review. Quentin W, Riedel-Heller SG, Luppa M, Rudolph A, Ko¨nig HH. Cost-of-illness studies of dementia: a systematic review focusing on stage dependency of costs. Acta Psychiatr Scand 2010;121:243–59. Review. Riedel-Heller SG, Busse A, Angermeyer MC. The state of mental health in old-age across the ‘old’ European Union– a systematic review. Acta Psychiatr Scand 2006;113:388–401. Review.
Riedel-Heller SG, Busse A, Aurich C, Matschinger H, Angermeyer MC. Incidence of dementia according to DSM-III-R and ICD10: results of the Leipzig Longitudinal Study of the Aged (LEILA75+), Part 2. Br J Psychiatry 2001; 179:255–60. United Nations, Department of Economic and Social Affairs, Population Division. World Population Prospects: The 2008 Revision, Highlights, Working Paper No. ESA/P/ WP.210. New York: UN, 2009. van der Flier WM, Scheltens P. Epidemiology and risk factors of dementia. J Neurol Neurosurg Psychiatry 2005;76(Suppl. 5):v2– 7. Review. Viswanathan A, Rocca WA, Tzourio C. Vascular risk factors and dementia: how to move forward? Neurology 2009;72:368–74. Review. Wancata J, Musalek M, Alexandrowicz R, Krautgartner M. Number of dementia sufferers in Europe between the years 2000 and 2050. Eur Psychiatry 2003;18:306–13. WHO. World Health Report 2003 – Shaping the future. Geneva: WHO, 2003. Wimo A, Winblad B, Jo¨nsson L. An estimate of the total worldwide societal costs of dementia in 2005. Alzheimers Dement 2007;3:81–91. Wimo A, Winblad B, Jo¨nsson L. The worldwide societal costs of dementia: Estimates for 2009. Alzheimers Dement 2010;6:98–103.
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