title: [Study on clustering of Yunnan unexplained sudden death in household and village].
abstract: OBJECTIVE
  To discuss the clustering of Yunnan unexplained sudden death (YUSD) in household and village.
  
  
  METHODS
  Fifty-two cases were found by YUSD surveillance system in 2005. Poisson distribution and beta-binomial distribution (BBD) were employed in studying the household distribution of the disease. Poisson distribution and negative binomial distribution (NBD) were employed in studying the village distribution of the disease.
  
  
  RESULTS
  BBD were fitted household distribution of YUSD very well (chi(2) = 0.25, P = 0.62), while Poisson distribution was consistent with it (chi(2) = 46.01, P < 0.001). And NBD were fitted village distribution of YUSD very well (chi(2) = 0.05, P = 0.58), however the consistency in Poisson distribution was not observed (chi(2) = 110.57, P < 0.001).
  
  
  CONCLUSIONS
  Household and village clustering of YUSD does exist.
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing 100050, China.
authors.forename: Jin-Ma
authors.initials: JM
authors.lastname: Ren
authors.forename: Yan-Rong
authors.initials: YR
authors.lastname: Zhao
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Huang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Shen
authors.forename: Xu
authors.initials: X
authors.lastname: Xie
authors.forename: Jian
authors.initials: J
authors.lastname: Cai
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Feng
authors.initials: F
authors.lastname: Cehn
authors.forename: Guang
authors.initials: G
authors.lastname: Zeng
mesh_terms: D015982:Bias; D016010:Binomial Distribution; D002423:Cause of Death; D002681:China / Q000453:epidemiology; D003645:Death, Sudden / Q000453:epidemiology*; D005190:Family; D006801:Humans