310 likes | 438 Views
A Multicriteria Model Applied in the Diagnosis of Alzheimer's Disease. Ana Karoline A. de Castro akcastro@gmail.com Plácido Rogério Pinheiro Mirian Caliope Dantas Pinheiro {placido, caliope}@unifor.br University of Fortaleza – Ceara - Brazil. Introduction.
E N D
A Multicriteria Model Applied in the Diagnosisof Alzheimer's Disease Ana Karoline A. de Castro akcastro@gmail.com Plácido Rogério Pinheiro Mirian Caliope Dantas Pinheiro {placido, caliope}@unifor.br University of Fortaleza – Ceara - Brazil
Introduction • Many studies show that there has been a progressive increase of the elderly population in the last years. • The main consequence of this fact, is the increase in life, expectancy and the increase of the prevalence of dementias. • Alzheimer’s disease is the most frequent cause of dementia. • Porto, C.S., Fichman, H.C., Caramelli, P., Bahia, V. S., Nitrini, R.: Brazilian Version of the Mattis Dementia Rating Scale Diagnosis of Mild Dementia in Alzheimer.s Disease, Arq Neuropsiquiatr 61(2-B) (2003) 339–345.
Introduction • Systems of classification with specific inclusion and exclusion criteria allow for the clinically probable definition and diagnosis of Alzheimer’s disease. • The main focus of this work is to develop a multicriteria model for aiding in decision making for the diagnosis of Alzheimer's disease.
Diagnosis of Alzheimer's Disease • Diagnosis of Alzheimer's disease is carried out in several steps. Initially, syndromic diagnosis is defined, which informs whether the patient presents the diagnostic criteria for dementia. • After Dementia is confirmed, etiological diagnosis follows, which informs which disease is causing the dementia. In this case, we are looking for Alzheimer's disease. • World Health Organization at http://www.who.int/classifications/icd/en/ • Hughes, C.P., Berg, L., Danzinger, W.L., Coben, L.A., Martin, R.L.: A New Clinical Scale for the Staging of Dementia, British Journal of Psychiatry 140 (1982) 566–572. • Mckhann, G.D., Drachman, D., Folstein, M., Katzman, R., Price, D., Stadlan, E.M.: Clinical Diagnosis of Alzheimer’s Disease: Report of the NINCDS-ADRDA Work Group under the Auspices of the Department of Health and Human Services Task Force on Alzheimer’s Disease, Neurology 34 (1984) 939–944.
Definition of Problem • In studies developed by (Castro,2007a) and (Castro,2007b) the application of the multicriteria model for aiding in diagnosis of Alzheimer's disease was presented. • Two MCDA tools were used to aid in solving the problem: • Hiview (www.catalyze.co.uk) • M-MACBETH (www.m-macbeth.com) • CASTRO, A. K. A.; PINHEIRO, P. R.; PINHEIRO, M. C. D.; Applying a Decision Making Model in the Early Diagnosis of Alzheimer’s Disease. In: Joint Rough Sets Symposium (JRS07), 2007. Proceedings of Joint Rough Sets Symposium. Berlin: Springer Verlag, 2007a. • CASTRO, A. K. A., PINHEIRO, P. R., PINHEIRO, M. C. D. A.; Multicriteria Model Applied in the Early Diagnosis of Alzheimer's Disease: A Bayesian Approach. In: International Conference on Operational Research for Development (ICORDVI), Brazil, 2007b.
Definition of Problem • In the present study, we sought to develop a multicriteria model that helps in the decision making related to the diagnosis of Alzheimer's disease. • This model consists of several steps that will be described below. • Initially were defined the problem value tree corresponding to the Fundamental point of view (FPV) that are used in evaluation of the diagnosis.
Definition of Problem - Describers • An FPV is operational in the moment that has a set of levels of associated impacts (describers). These impacts are defined for Nj, that can be ordered in decreasing form according to the describers (Bana, 2003). • For the evaluation of each FPV, the possible states were defined. Each FPV has a different quantity of states. These states were defined according to the exams or questions involved for each describer. • Its important remember that the describers has a structure of complete pre-order, otherwise, a superior level is always preferable a least level. • Bana & Costa, C.A., Corte, J.M.D., Vansnick, J.C. Macbeth, LSE-OR Working Paper, (2003).
Definition of Problem - Analysis of Impacts • In this step, the analysis of impacts is carried out, according to each FPV: (i) the lowest and highest values of the impacts; and (ii) the relevant aspects of the distribution of the impacts in each one. • In this work, for each describer, the same values were considered to get the value function for each FPV. Therefore, scores higher than 60, obtained through the judgments matrixes were considered risk describers during the evaluation of diagnosis.
Definition of Problem - Evaluation • After the definition of the FPVs family and the construction of the describers, the next step is the construction of the cardinal value scales for each FPV. • After evaluating the alternatives of all the FPVs individually, an evaluation of the FPVs in one matrix only was carried out.
Definition of Problem - Results • In this step we show the final result of the model, the contribution of the criterion for the diagnosis of Alzheimer's disease. • We can see the describer values for each criteria. With these values we can conclude that the questions that are part of these describers should be preferentially applied during the definition of diagnosis of Alzheimer's disease.
Definition of Problem - Evaluation Results • In this step the value analyses of the sensitivity and the dominance of potential actions in the process of evaluation to discover which questions are most relevant for diagnosis of Alzheimer's disease by using data sets. HIVIEW software (Keysalis, 1995) was used to carry out these analyses. • Keysalis. Hiview for Windows. London: Krysalis, (1995).
Application of the Multicriteria Model • For the application of the model two scenarios: 1) The battery of standardized assessments developed by The Consortium to Establish a Registry for Alzheimer's disease (CERAD) 2) The questionnaire with 120 questions that was used in a study realized in the city of Sao Jose dos Campos, SP, Brazil were used.
Scenario 1 • The original mandate of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) in 1986 was to develop a battery of standardized assessments for the evaluation of cases with Alzheimer's disease who were enrolled in NIA-sponsored Alzheimer's Disease Centers (ADCs) or in other dementia research programs (Morris, 1989). • CERAD was designed to create uniformity in enrollment criteria and methods of assessment in clinical studies of Alzheimer's Disease and to pool information collected from sites joining the Consortium. • Morris JC, Heyman A, Mohs RC, et al. The Consortium to Establish a Registry for Alzheimer's Disease (CERAD): Part 1. Clinical and Neuropsychological Assessment of Alzheimer's Disease. Neurology,39(1989) 1159-1165.
Scenario 1- Describers • Each FPV has a different quantity of states. The FPV1 has 3 states. The FPV2 has 5 states. The FPV3 has 3 states. The FPV4 has 3 states. The FPV5 has 3 states. The FPV6 has 3 states. The FPV7 has 13 states.
Scenario 1- Evaluation • Next, the evaluation of the FPVs was made through the construction of the judgment matrixes.
Scenario 1- Evaluation • In the last step of the application of the model we made the global evaluation of the actions when they are confronted with the seven FPVs.
Scenario 1- Evaluation • It was found that FPV1 to FPV7 have a total participation of 19,8%, 13,9%, 17,8%, 10,9%, 1,0%, 17,8% and 18,8%. • The action N03 proved to be potentially better with 85 points and the action N01 proved to be potentially least.
Scenario 2 • We used information obtained from the study realized in 2005 with 235 elderly people in the city of Sao Jose dos Campos, SP, Brazil. • In this study a questionnaire with 120 questions that supplied demographic-social data, analyzed the subjective perception of the elderly, their mental and physical health (cognitive and emotional aspects), day-to-day independence, in addition to family and social support and the use of services (Belderrain, 2006). • Belderrain, M. C. N., Silva, A. C. S., Vianna, P. V. C. Functional capacity of the elderly in city of Sao Jose dos Campos - Sao Paulo - Brazil. In: 21st European Conference on Operational Research - EURO XXI, Iceland. EURO XXI Proceedings, (2006).
Scenario 2- Describers • The FPV1 has 4 states. The FPV2 has 6 states. The FPV3 has 7 states. The FPV4 has 8 states. The FPV5 has 6 states. The FPV6 has 4 states.
Scenario 2- Evaluation • Next, the evaluation of the FPVs was made through the construction of the judgment matrixes.
Scenario 2- Evaluation • In the last step of the application of the model we made the global evaluation of the actions when they are confronted with the six FPVs.
Scenario 2- Evaluation • It was found that FPV1 to FPV6 have a total participation of 14,3%, 22,9%, 14,3%, 14,3%, 20,0% and 14,3%. • Thus, action N04 proved to be potentially better with 99 points and the action N01 proved to be potentially least.
Comparation of the Results • In scenario 1 we have the FPV7 (Neuro-pathological Diagnoses) as the criterion with the largest number of describers which obtained the minimum values required by the model. This result shows the importance of the definition of the diagnosis of Alzheimer's. • This is merely to underline the importance of this criterion for the solution of this problem. In scenario 2 we have FPV4 (Community Affairs) as the criterion with the largest number of describers which obtained the minimum values required by the model.
Comparation of the Results • Analyzing the characteristics of these two criteria, we see that despite being in different scenarios, they have similarities, as both the FPV7 in scenario 1 and FPV4 in scenario 2 are related primarily, the possible mental health problems that may occur with the patient and that may cause confusion in the definition of the diagnosis of Alzheimer's disease. The first result was obtained from the judgment of matrixes through the M-MACBETH software.
Conclusions • The MACBETH multicriteria method was used to aid in decision making. The criteria were defined according to the CERAD areas of assessment. In the questionnaire applied in the Brazilian study we defined the criteria based on to demographic-social data, analyzed the subjective perception of the elderly, their mental and physical health. • The questions that make up the battery of assessments and in the questionnaire were defined as the describers of the problem. With this information, the judgment matrixes were constructed using M-MACBETH software. • After evaluating the matrixes, a ranking was obtained showing all the questions, from most important to least important with respect to the diagnosis of Alzheimer's. At the end of this study, a comparison was made of the results obtained in the application of the model in both data sets.
Future Work • An extension of the model is in the submission process (Castro, 2008) using Bayesian Networks. We defined the mapping of the questions of CERAD and in the questionnaire applied in the Brazilian study and through these mappings we can observe the questions of the biggest decisive impact for the diagnosis. • In addition, with this Bayesian Network, we structured a multicriteria model that shows the questions of the biggest decisive impact for the diagnosis. Were showing the percentage of elderly people that presented the symptoms of Alzheimer’s disease. • Castro, A. K. A., Pinheiro, P. R., Pinheiro, M. C. D. Applying Bayesian Networks and a Multicriteria Model in the Diagnosis of Alzheimer's Disease. BMC Medical Informatics and Decision Making, (2008). ISSN: 1472-6947. Paper has been submitted.
Future Work • As a future project, this model can be extended with the inclusion of new criteria or new models which can be developed using other data sets (Belderrain, 2006). • Belderrain, M. C. N., Silva, A. C. S., Vianna, P. V. C. Functional capacity of the elderly in city of Sao Jose dos Campos - Sao Paulo - Brazil. In: 21st European Conference on Operational Research - EURO XXI, Iceland. EURO XXI Proceedings, (2006).
Acknowledgment • The authors thank the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Amanda Cecilia Simoes da Silva and Mischel Carmem Neyra Belderrain (Instituto Tecnologico de Aeronautica) for the divulgation of the data utilized in this case study. • We are thankful to FUNCAP for the support we have received for this project.