The Cretan Aging Cohort: Cohort Description and Burden of Dementia and Mild Cognitive Impairment

Abstract

Our aim was to explore the burden of dementia in the Cretan Aging Cohort, comprised of 3140 persons aged 60 years (56.8% women, 5.8 + 3.3 years formal education, 86.2% living in rural areas) who attended selected primary health-care facilities on the island of Crete, Greece. In the first study phase, a formal diagnosis of dementia had been reached in 4.0% of the participants. However, when selected 505 participants underwent thorough neuropsychiatric evaluation in the second phase of this study (344 with Mini-Mental State Examination [MMSE] <24 and 161 with MMSE 24), and results were extrapolated to the entire cohort, the prevalence of dementia and mild cognitive impairment was estimated at 10.8% (9.7%-11.9%) and 32.4% (30.8%-34.0%), respectively. Using both the field diagnostic data and the extrapolated data, the highest dementia prevalence (27.2%) was found in the 80-to 84year-old group, who also showed the lowest educational level, apparently due to lack of schooling during World War II.

Diagnosing dementia and cognitive dysfunction in the elderly in primary health care: A systematic review

“…Although the number of diagnosed patients is substantially larger than the prevalence suggested in the literature, it is relevant to observe that some of the studies suggested the existence of undiagnosed older adults in primary health care. For instance, Zaganas et al 32 stated in their study that 60% of the older adults remained without a dementia/MCI diagnosis in primary health care until further in-depth neuropsychiatric evaluation. Similarly, Parmar et al 33 evaluated medical records from the Canadian primary health care system and found no cases of MCI diagnosis.…”

Cognitive impairment in a primary healthcare population: a cross-sectional study on the island of Crete, Greece

“…The objective of the overall multi-disciplinary study (Thales MNSAD) 22 was to enrol a minimum of 250 persons meeting formal Diagnostic and Statistical Manual of Mental Disorders (DSM) IV criteria for dementia. Assuming an 8% (95% CI 7.1% to 9.0%) prevalence of any type of dementia 31 among PHC visitors over 60 years of age, a minimum sample size of 3200 participants was estimated.…”

“…However, analysis of data from sub-group of the present sample defined by the corresponding DSM-IV criteria 303 of 344 (88%) participants with MMSE scores<24 were diagnosed as having either MCI or dementia. 22 In addition to the above, in our study, we have excluded from recruitment patients visiting PHC facilities for an emergency, thus we have excluded delirium or other acute causes that may have an effect on cognition. As the cut-offs used in our study have previously been validated for detecting severe MCI or dementia, 27 we are somewhat confident that cognitive impairment as judged by education-adjusted low MMSE in our population corresponds roughly to severe CI or dementia.…”

“…In this respect, we have already reported that as many as 60% of patients with dementia have not received a diagnosis before seeing a specialist. 22 Moreover, specific conditions such as depression could be used as an alarm signal to investigate cognitive impairment.…”

“…21 In this context, a multi-disciplinary research network was established at the Faculty of Medicine, University of Crete, Greece including researchers and practitioners from various medical disciplines (Thales MNSAD-Multidisciplinary Network for the Study of Alzheimer's disease) to study the magnitude of this health problem and discuss the care challenges for the healthcare services. 22 The present report uses baseline data from the PHC team with the aim to inform healthcare providers and policy-makers regarding the extent of cognitive impairment in the PHC population, and associations with demographic and clinical risk factors, as judged by the Mini-Mental State Examination (MMSE). Specific objectives were the following: ► To report the extent of elders with low scores on a widely adopted screening instrument for dementia (MMSE) among those served by primary care centres in the prefecture of Heraklion Crete, Greece.…”