***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE To determine the prevalence of dementia  in Thai people with age 45 years and above . MATERIAL AND METHOD This project used a cross sectional research design to study the prevalence of dementia in Chiang Mai . Door-to-door technique was assigned in condition with multi-stage probability r and om sampling to obtain subjects representing the population of Chiang Mai between Oct 2004 and Sep 2005 . The research ers collected the data from the subjects aged 45 years and above . All subjects were located from every Amphurs of Chiang Mai . They were first screened with Thai Mini Mental State Examination ( TMSE ) and Thai Beck Depression Inventory ( BDI ) . The subjects whose TMSE was less than 24 were assessed and diagnosed by a neurologist . Subjects who were determined as having dementia might be laboratory analyzed and classified based on DSM-IV and NINDS-AIREN criteria . RESULTS The authors enrolled 2,311 people and screened them with Batteries test . One thous and four hundred ninety two people qualified with 610 males and 882 females , whose mean age was 59.7 + /- 10.4 years . The authors found that among the 35 people with dementia , the mean age was 67.9 + /- 8.9 years ( 45 - 88 years ) . The prevalence of dementia among the study participants was 2.35 % . In the present study , Alzheimer 's disease was the most common type of dementia diagnosed ( 75.0 % ) and vascular dementia was the second most commonly diagnosed ( 12.5 % ) . CONCLUSION The prevalence of dementia  in Chiang Mai was 2.35 % , which does not differ from the previous study Alzheimer 's disease was the most common type of dementia diagnosed Background / Aims : The prevalence of dementia and cognitive impairment not dementia was investigated in the Caerphilly Prospect i ve Study cohort ( men currently aged 65–84 years ) . Methods : Of 1,633 men eligible for cognitive screening , 1,225 ( 75 % ) were seen , with those failing the screening criteria ( CAMCOG < 83 or decline in CAMCOG > 9 ) being neurologically examined . Results : For dementia , diagnosed by DSM-IV criteria , the population prevalence was 5.2 % rising to 6.1 % in the screened population . For cognitive impairment not dementia , the prevalence in the screened population was 15.6 % giving an overall prevalence of cognitive impairment of 21.8 % . Prevalence rose fivefold between ages of 65 and 84 years to reach over 50 % . Conclusion : These figures are likely to underestimate actual prevalence in this population , and developing effective interventions should be a public health priority BACKGROUND Vascular dementia ( VaD ) has been considered to be more prevalent than Alzheimer disease in Japan . However , this might be the result of overdiagnosis stemming from some problematic diagnosis of VaD or of the frequent use of magnetic resonance imaging to detect cerebrovascular disease in older adults . OBJECTIVES We investigated the prevalence of dementia and the ratios of dementing diseases . The effects of different criteria for VaD ( DSM-IV , Alzheimer 's Disease Diagnostic and Treatment Centers [ ADDTC ] , and National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l'Enseignement en Neurosciences [ NINDS-AIREN ] ) were considered . Hippocampal atrophy and vascular contribution to dementia were evaluated using magnetic resonance imaging findings . METHODS We targeted all residents 65 years and older ( n = 3207 ) in Tajiri , Japan , and examined 1654 ( participant group 1 ) . Of these , 564 ( participant group 2 ) were r and omly selected , and 497 underwent magnetic resonance imaging and diagnosis of dementing diseases . RESULTS We found the overall prevalence of dementia to be 8.5 % ( 141/1654 ) in participant group 1 . Of these , 21 ( 14.9 % ) had a history of stroke . Of the 113 participants who had a history of stroke independent of dementia , 18.6 % ( 21/113 ) were demented . For participant group 2 ( n = 497 ) , 32 were demented . The ratio among the dementia for probable VaD based on the NINDS-AIREN criteria was 18.8 % ( 6/32 ) , whereas that for ischemic vascular dementia was 31.3 % ( 10/32 ) according to the ADDTC criteria . CONCLUSION We confirmed the overall prevalence of dementia in adults 65 years and older to be 8.5 % . We found that VaD was not a common disorder according to the NINDS-AIREN criteria . Rather , the condition of possible Alzheimer disease with cerebrovascular disease was more common Objective : To estimate the incidence and survival rates of total and cause specific dementia in a general Japanese population . Methods : A total of 828 subjects without dementia , aged 65 years or over , were followed-up prospect ively for 17 years . Dementia was subdivided into cause specific subtypes : namely , Alzheimer ’s disease ( AD ) , vascular dementia ( VD ) , dementia with Lewy bodies ( DLB ) , combined dementia and other types of dementia . During the follow-up , 275 subjects developed dementia ;  of these , 251 ( 91.2 % ) were evaluated morphologically , with 164 subjected to brain autopsy examination  and the remaining 87 to neuroimaging .  Results : The incidences of total dementia , AD , VD , DLB , combined dementia and other types of dementia were 32.3 ( n = 275 ) , 14.6 ( 124 ) , 9.5 ( 81 ) , 1.4 ( 12 ) , 3.8 ( 33 ) , and 3.1 ( 16 ) per 1000 person years , respectively . The incidences of AD , combined dementia and other types of dementia rose with increasing age , particularly after the age of 85 years , but this tendency was not observed for VD or DLB . The survival curve of dementia cases aged 65–89 years was significantly lower than that of age and sex matched controls ( 10 year survival rate , 13.6 % vs 29.3 % ; hazard ratio 1.67 ; 95 % confidence interval 1.31 to 2.13 ) . The 10 year survival rates were not significantly different among dementia subtypes . Conclusions : Our findings suggest that the Japanese elderly population has a high risk for the development of dementia , specifically AD and VD , and once dementia is established , the risk of death is considerable Objective : To determine overall and age-specific incidence rates of AD in a rural , population -based cohort in Ballabgarh , India , and to compare them with those of a reference US population in the Monongahela Valley of Pennsylvania . Methods : A 2-year , prospect i ve , epidemiologic study of subjects aged ≥55 years utilizing repeated cognitive and functional ability screening  , followed by st and ardized clinical evaluation using the Diagnostic and Statistical Manual of Mental Disorders , 4th edition , and the National Institute of Neurological and Communicative Disorders and Stroke – Alzheimer ’s Disease and Related Disorders Association criteria for the diagnosis , and the Clinical Dementia Rating scale for the staging , of dementia and AD . Results : Incidence rates per 1000 person – years for AD with CDR ≥0.5 were 3.24 ( 95 % CI : 1.48–6.14 ) for those aged ≥65 years and 1.74 ( 95 % CI : 0.84–3.20 ) for those aged ≥55 years . St and ardized against the age distribution of the 1990 US Census , the overall incidence rate in those aged ≥65 years was 4.7 per 1000 person – years , substantially lower than the corresponding rate of 17.5 per 1000 person – years in the Monongahela Valley . Conclusion : These are the first AD incidence rates to be reported from the Indian subcontinent , and they appear to be among the lowest ever reported . However , the relatively short duration of follow-up , cultural factors , and other potential confounders suggest caution in interpreting this finding BACKGROUND The APOE*E4 allele of the gene for apolipoprotein E ( APOE ) has been reported as a risk factor for Alzheimer disease ( AD ) to varying degrees in different ethnic groups . OBJECTIVE To compare APOE*E4-AD epidemiological associations in India and the United States in a cross-national epidemiological study . DESIGN Case-control design within 2 cohort studies , using st and ardized cognitive screening and clinical evaluation to identify AD and other dementias and polymerase chain reaction to identify APOE genotyping . PARTICIPANTS Rural community sample s , aged 55 years or older ( n=4450 ) in Ballabgarh , India , and 70 years or older ( n=886 ) in the Monongahela Valley region of southwestern Pennsylvania . MAIN OUTCOME MEASURES Criteria of the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer 's Disease and Related Disorders Association for probable and possible AD and Clinical Dementia Rating ( CDR ) scale for dementia staging . RESULTS Frequency of APOE*E4  was significantly lower ( P<.001 ) in Ballabgarh vs the Monongahela Valley ( 0.07 vs 0.11 ) . Frequency of probable or possible AD , with CDR of at least 1.0 , in the Indian vs US sample s , was as follows : aged 55 to 69 years , 0.1 % ( Indian sample only ) ; aged 70 to 79 years , 0.7 % vs 3.1 % ; aged 80 years or older , 4.0 % vs 15.7 % . Among those aged 70 years or older , adjusted odds ratios ( 95 % confidence interval ) for AD among carriers of APOE*E4 vs noncarriers were 3.4 ( 1.2 - 9.3 ) and 2.3 ( 1.3 - 4.0 ) in the Indian and US sample s , respectively , and not significantly different between cohorts ( P=. 20 ) . CONCLUSION This first report of APOE*E4 and AD from the Indian subcontinent shows very low prevalence of AD in Ballabgarh , India , but association of APOE*E4 with AD at similar strength in Indian and US sample s. Arch Neurol . 2000 Background Despite worldwide recognition of the burden of dementia , no epidemiological data is yet available in Portugal . The objective of this study is to estimate the prevalence and describe the pattern of cognitive impairment with dementia or no dementia ( CIND ) in rural and urban population s from Northern Portugal . Methods Two r and om sample s of residents aged 55 to 79 years in rural and urban communities were drawn from the health centres registries to be screened for cognitive impairment . The screening criteria for dementia were an abnormal Mini-Mental State Examination ( MMSE ) score or a Blessed Dementia Scale score . After excluding those who tested positive for dementia , cut-off points for CIND were set at 1 st and ard deviation below the mean of the MMSE according to educational level . All those who screened positive either for dementia or CIND were examined by a neurologist for establishing a definitive diagnosis . Results The prevalence of cognitive impairment was higher in rural than in urban population s , 16.8 % ( 95 % CI : 14.3 - 19.8 % ) vs. 12.0 % ( 95%CI : 9.3 - 15.4 % ) , with a rural/urban prevalence ratio ( PR ) of 2.16 ( 95 % CI : 1.04 - 4.50 ) in the eldest and 2.19 ( 95 % CI : 1.01 - 4.76 ) in persons with vascular risk factors . The prevalence of dementia was 2.7 % ( 95 % CI : 1.9 - 3.8 % ) with a rural/urban PR = 2.1 and the prevalence of CIND was 12.3 % ( 95 % CI : 10.4 - 14.4 % ) and PR = 1.3 . The prevalence of dementia increases exponentially with age and in those with cerebrovascular disease or other comorbid conditions while the prevalence of CIND , besides these factors , is also higher in persons with low levels of education or vascular risk factors . Alzheimer 's and vascular disease were equally likely aetiologies of dementia ( 38.7 % ) , the later more common in men PR(F : M = 0.3 ) as opposed to the former PR(F : M = 2.0 ) . Vascular CIND , associated either with cerebrovascular disease or vascular risk factors was more frequent ( 39.7 % ) then depression ( 18.4 % ) or any other aetiology . Conclusions The prevalence of cognitive impairment is higher in rural compared with urban population s. This is shown in the synergy between age and rurality , with the rural/urban prevalence ratio increasing with age . In this relatively young population from Northern Portugal , cerebrovascular disease as 
    Output:
    
The burden of AD dementia is substantial .
Significant gaps in our underst and ing of its epidemiology were identified , even in a high-income country such as Canada .