title: Small area clustering of under-five children's mortality and associated factors using geo-additive Bayesian discrete-time survival model in Kersa HDSS, Ethiopia.
abstract: BACKGROUND
  Child mortality reflects a country's level of socio-economic development and quality of life. In Ethiopia, limited studies were conducted on under-five mortality and almost none of them tried to identify the spatial effect on mortality. Thus, this study explored the small area clustering of under-five mortality and associated factors in Kersa HDSS, Eastern Ethiopia.
  
  
  METHODS
  The study population included all children under the age of five years during the time September, 2008-august 31, 2012 which are registered in Kersa Health and Demographic Surveillance System (Kersa HDSS). A flexible Bayesian geo-additive discrete-time survival mixed model was used.
  
  
  RESULTS
  Some of the factors that are significantly associated with under-five mortality, with posterior odds ratio and 95% credible intervals, are maternal educational status 1.31(1.13,-1.49), place of delivery 1.016(1.013-1.12), no of live birth at a delivery 0.35(0.23,1.83), low household wealth index 1.26(1.10 1.43) middle level household wealth index 0.95 (0.84 1.07) pre-term duration of pregnancy 1.95(1.27,2.91), post-term duration of pregnancy 0.74(0.60,0.93) and antenatal visit 1.19(1.06, 1.35). Variation was noted in the risk of under-five mortality by the selected small administrative regions (kebeles).
  
  
  CONCLUSIONS
  This study reveals geographic patterns in rates of under-five mortality in those selected small administrative regions and shows some important determinants of under-five mortality. More importantly, we observed clustering of under-five mortality, which indicates the importance of spatial effects and presentation of this clustering through maps that facilitates visuality and highlights differentials across geographical areas that would, otherwise, be overlooked in traditional data-analytic methods.
authors.affiliation: Department of Statistics, College of Computing and Informatics, Haramaya University, P.O.Box 138, Dire Dawa, Ethiopia; Kersa Health and Demographic Surveillance System (Kersa HDSS), P.O. Box 235, Harar, Ethiopia. Electronic address: melkyed@gmail.com.
authors.forename: Melkamu
authors.initials: M
authors.lastname: Dedefo
authors.affiliation: College of Health and Medical Sciences, Haramaya University, P.O. Box 1494, Harar, Ethiopia; Kersa Health and Demographic Surveillance System (Kersa HDSS), P.O. Box 235, Harar, Ethiopia. Electronic address: olemessa@yahoo.com.
authors.forename: Lemessa
authors.initials: L
authors.lastname: Oljira
authors.affiliation: College of Health and Medical Sciences, Haramaya University, P.O. Box 1494, Harar, Ethiopia; Kersa Health and Demographic Surveillance System (Kersa HDSS), P.O. Box 235, Harar, Ethiopia. Electronic address: negaassefa@yahoo.com.
authors.forename: Nega
authors.initials: N
authors.lastname: Assefa
mesh_terms: D001499:Bayes Theorem; D046688:Child Mortality; D002675:Child, Preschool; D016000:Cluster Analysis; D005002:Ethiopia; D005260:Female; D062305:Geographic Mapping; D006801:Humans; D007223:Infant; D008297:Male; D015233:Models, Statistical; D016017:Odds Ratio; D012307:Risk Factors; D012959:Socioeconomic Factors; D016019:Survival Analysis
keywords: Bayesian geo-additive model; Kersa HDSS; Spatial clustering; Under-five mortality