Predictive Analyses of Institutionalisation in Dementia and Mild Cognitive Impairment Patients

Poster Presentations P2 one patient with AD, at an average screening cost of £5,100 per patient diagnosed with AD. Compared to a scenario without screening or pharmacologic treatment, screening reduces health care costs by £2,500 per patient. Including savings from costs of caregiver time, overall societal savings are almost £7,000 per AD patient diagnosed. Health benefits are also substantial. Patients screened and treated with donepezil spend on average almost 5 months less with MMSE scores below 10 and over 3 months longer living in the community. Quality adjusted life years (QALYs) improve by an average of 0.18. Screening also leads to important gains when compared to a scenario where treatment with donepezil is initiated upon diagnosis in the absence of screening. Results are sensitive to estimates of patient care costs and the probability of patients reporting subjective memory complaints. In probabilistic sensitivity analyses, screening leads to savings or is highly cost-effective in the great majority of cases. Conclusions: Although screening has significant upfront costs, identifying AD patients early results in cost savings and health benefits compared to no treatment or treatment in the absence of screening. P2-045

PREDICTIVE ANALYSES OF INSTITUTIONALISATION IN DEMENTIA AND MILD COGNITIVE IMPAIRMENT PATIENTS

Michael Woodward1, Henry Brodaty2, Karyn Boundy3, David Ames4, 1 Austin Health, Melbourne, Australia; 2Prince of Wales Hospital and Primary Dementia Collaborative Research Centre, Sydney, Australia; 3 The Queen Elizabeth Hospital, Adelaide, Australia; 4St Georges Hospital, Melbourne, Australia. Contact e-mail: Michael.WOODWARD@ austin.org.au Background: To examine predictive factors for institutionalisation after 12months in patients with dementia or mild cognitive impairment who are still living at home. Methods: The PRIME (Prospective Research In MEmory clinics) study is a non-prescriptive, longitudinal, multiple cohort design employing prospective real time acquisition of clinical, treatment, health status and economic data collected at nine sites within Australia that has finished recruitment with 970 patients. To date, 543 patients with a diagnosis of mild cognitive impairment (MCI) (24.8%) or dementia (72.2%) enrolled in PRIME have data at both baseline and 12-months. For fields that were missing less than 20% of values, a median/mode method of imputation was used. Variables examined were: MCI diagnosis, acetylcholinesterase inhibitor (AChI) use, living arrangements, sex, psychotropic medication use, support group usage, age, service usage, Clinical Dementia Rating score (CDR), Zarit Burden Inventory (ZBI), Mini-mental State Examination, Functional Autonomy Measurement System, and Neuropsychiatric Index. Forward selection logistic regression was used to construct a parsimonious model including predictors with p-values less than 0.2. The impact of imputation was assessed by re-running the final regression models produced using only patients with complete sets of data for the identified predictors. P-values less than 0.05 were considered significant in the final, descriptive model. Results: Of the patients with 12-month data, 33 were institutionalised within 12-months of enrolling in PRIME. The odds ratios produced by the model were: use of AChI v none [OR 0.33, 95%CI 0.13,0.81]; MCI v dementia [OR 0.24, 95%CI 0.03,2.14]; each extra year of age[OR 1.04, 95%CI 0.98,1.11]; patient living with spouse v other [OR 0.14, 95%CI 0.06,0.34]; service use [OR 1.26 per service accessed, 95%CI 0.93,1.71]; each additional point in CDR[OR 2.88, 95%CI 1.65,5.02]; and each additional point in the ZBI [OR 1.05, 95%CI 1.02,1.07]. Similar ORs were produced using only patients with complete data, though with slightly wider confidence intervals, indicating the imputation of missing values was appropriate. Conclusions: The use of an AChI, and living with their spouse were associated with a lower risk of institutionalisation. Higher CDR scores and higher caregiver stress were associated with a higher likelihood of the patient being institutionalised. P2-046

TOWARD A MULTI-DIMENSIONAL FORMULATION OF ALZHEIMER’S DISEASE PATHOGENESIS AND PATHOPHYSIOLOGY

Rodrigo O. Kuljis, The Brain-Mind Project, Inc., Galveston, TX, USA. Contact e-mail: [email protected]

P275

Background: Neurodegenerative disorders constitute a set of heterogeneous conditions lacking a satisfactory, unanimously agreed unifying conceptual scheme. This hampers progress in adequately understanding them in order to develop effective treatments and prevention. Methods: We propose that resolving this conundrum requires addressing in an integrated fashion the multiple dimensions and scales of organization of the Central Nervous System, that transcend the conventional boundaries of Biochemistry/Molecular Biology, Systems Neuroscience and Nosology, among others, as well as the short-term time scales usually considered in this approach. Results: This proposal offers a more integrative conceptual scheme to tackle the complexity of neurodegenerative disorders that offers considerable advantages over the present, admittedly fruitful, but yet not sufficiently successful and increasingly "atomizing" analytic approach to Alzheimer’s disease and most other neurodegenerative conditions that cause dementia. Conclusions: Integration of an increasing amount of levels of analysis – well beyond the partially interdisciplinary approach already underway – is essential to achieve an adequate understanding of neuron-targeting dementias. This will be far more successful in devising effective treatments and prophylaxis than purely biochemical and molecular strategies. Supported by an unrestricted grant from Encephalogistics, Inc. and The Brain-Mind Project P2-047

TEMPORAL ORIENTATION IS THE BEST DISCRIMINATIVE ITEM OF THE FOLSTEIN’S MINI MENTAL STATUS EXAMINATION

Eleonora d’Orsi1, Andre´ Junqueira Xavier2, Daniel Sigulem3, Emil Kupek1, Luiz Roberto Ramos4, 1Universidade Federal de Santa Catarina, Floriano´polis, Brazil; 2Universidade Federal de Sa˜o Paulo, Departamento de Informa´tica em Sau´de, Sa˜o Paulo, Brazil; 3Universidade Federal de Sa˜o Paulo, Departmento de Informa´tica em Sau´de, Sa˜o Paulo, Brazil; 4Universidade Fedral de Sa˜o Paulo, Departamento de Medicina Preventiva, Sa˜o Paulo, Brazil. Contact e-mail: [email protected] Background: Folstein‘s Mini Mental Status Examination (MMSE) is a traditional screening instrument in geriatrics but may be difficult to implement for subjects with low educational level. Methods: This analysis used the first (1991/1992) and second (1993/1994) wave interviews of the cohort study Epidoso in Sa˜o Paulo, Brazil, with 1667 elderly participants. The following MMSE items have been tested: temporal orientation, spatial orientation, short term memory, attention & calculus, long term memory, nomination and sequential commands. Regression-based dichotomous discriminant analysis was applied in software Stata 9.0. The statistical parameters were the percentage correctly classified individuals, sensitivity and specificity of the model. Cognitive impairment was defined as MMSE score below 24 points. The discriminative capacity of the items was tested in relation to cognitive impairments at 2 moments: in the first survey and 2 years later. A model with all items of MMSE was elaborated and its discriminative power verified. Then, the models with individual items were tested and compared with those of the complete model. Results: In the first survey, the item temporal orientation correctly predicted 87.22% of the cognitively impaired individuals, with sensitivity of 91.92% and specificity of 76,34%. In the second survey, the same item correctly predicted 81.05%, with sensitivity of 86,55% and specificity of 59,19%. The temporal orientation was the only item with the same capacity of prediction as that of the complete model with all 30 MMSE items. Conclusions: The loss of temporal orientation compromises the social life of the elderly and may serve as an early sign of cognitive impairments that is relatively robust regarding the educational level of the participants. Temporal orientation is the component that best discriminates cognitive impairments among the MMSE items and can be used for the screening purpose in the absence of the complete score. P2-048

PARADIGM SHIFT FROM ALZHEIMER-CENTRIC VIEW OF BRAIN AGING AND DEMENTIA: DYNAMIC POLYGON HYPOTHESIS

Majid Fotuhi1, Vladimir Hachinski2, Peter Whitehouse3, 1LifeBridge Health Brain & Spine Institute and Johns Hopkins Hospital,