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Penalized likelihood and multi-objective spatial scans for the detection and inference of irregular clusters.
Cançado, André L F; Duarte, Anderson R; Duczmal, Luiz H; Ferreira, Sabino J; Fonseca, Carlos M; Gontijo, Eliane C D M.
Afiliação
  • Cançado AL; Department of Statistics, Universidade Federal de Minas Gerais, Belo Horizonte/MG, Brazil.
Int J Health Geogr ; 9: 55, 2010 Oct 29.
Article em En | MEDLINE | ID: mdl-21034451
BACKGROUND: Irregularly shaped spatial clusters are difficult to delineate. A cluster found by an algorithm often spreads through large portions of the map, impacting its geographical meaning. Penalized likelihood methods for Kulldorff's spatial scan statistics have been used to control the excessive freedom of the shape of clusters. Penalty functions based on cluster geometry and non-connectivity have been proposed recently. Another approach involves the use of a multi-objective algorithm to maximize two objectives: the spatial scan statistics and the geometric penalty function. RESULTS & DISCUSSION: We present a novel scan statistic algorithm employing a function based on the graph topology to penalize the presence of under-populated disconnection nodes in candidate clusters, the disconnection nodes cohesion function. A disconnection node is defined as a region within a cluster, such that its removal disconnects the cluster. By applying this function, the most geographically meaningful clusters are sifted through the immense set of possible irregularly shaped candidate cluster solutions. To evaluate the statistical significance of solutions for multi-objective scans, a statistical approach based on the concept of attainment function is used. In this paper we compared different penalized likelihoods employing the geometric and non-connectivity regularity functions and the novel disconnection nodes cohesion function. We also build multi-objective scans using those three functions and compare them with the previous penalized likelihood scans. An application is presented using comprehensive state-wide data for Chagas' disease in puerperal women in Minas Gerais state, Brazil. CONCLUSIONS: We show that, compared to the other single-objective algorithms, multi-objective scans present better performance, regarding power, sensitivity and positive predicted value. The multi-objective non-connectivity scan is faster and better suited for the detection of moderately irregularly shaped clusters. The multi-objective cohesion scan is most effective for the detection of highly irregularly shaped clusters.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Transtornos Puerperais / Análise por Conglomerados / Vigilância da População / Doença de Chagas Tipo de estudo: Diagnostic_studies / Health_economic_evaluation / Screening_studies Limite: Animals / Female / Humans / Newborn País/Região como assunto: America do sul / Brasil Idioma: En Revista: Int J Health Geogr Assunto da revista: EPIDEMIOLOGIA / SAUDE PUBLICA Ano de publicação: 2010 Tipo de documento: Article País de afiliação: Brasil País de publicação: Reino Unido

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Transtornos Puerperais / Análise por Conglomerados / Vigilância da População / Doença de Chagas Tipo de estudo: Diagnostic_studies / Health_economic_evaluation / Screening_studies Limite: Animals / Female / Humans / Newborn País/Região como assunto: America do sul / Brasil Idioma: En Revista: Int J Health Geogr Assunto da revista: EPIDEMIOLOGIA / SAUDE PUBLICA Ano de publicação: 2010 Tipo de documento: Article País de afiliação: Brasil País de publicação: Reino Unido