title: Rural children active trachoma risk factors and their interactions.
abstract: BACKGROUND
  Trachoma is a serious public health problem in rural Ethiopia. The aim of this investigation was to provide in-depth statistical analysis of the risk factors associated with active trachoma among children of age 1-9 years of Kedida Gamela district, in Ethiopia.
  
  
  METHODS
  A community based cross-sectional survey of trachoma was conducted in six selected rural kebeles of Kedida Gamela district, in Ethiopia from June 10-25, 2014. A total of 377 children (ages 1-9 years) were included in the study using two stage cluster sampling. All children were examined for trachoma by nurse data collectors supervised by ophthalmic supervisors using the WHO simplified clinical grading system. Ordinal survey logistic regression model was used to identify risk factors. Data analysis was done using SAS version 9.3.
  
  
  RESULTS
  The best fit proportional odds model was identified to be the main effects and two-way and three-way interactios. Keeping cattle in the house was found to have a protective effect (OR=0.138, p-value=0.0003). The household wealth will have a more protective effect if the child attends school. Washing face with soap and water once a day has equivalent protective effect as washing face three-or-more times a day with water only.
  
  
  CONCLUSIONS
  The 2-way and 3-way significant interactions effects unfolded some of the controversies derived from similar studies on trachoma risk factors. The findings would suggest integrated effort to address two or three factors simultaneously is more fruitful than any novel intervention targeted to address a single risk factor.
authors.affiliation: Department of Statistics, Bahir Dar University, Bahir Dar, Ethiopia.
authors.forename: Essey Kebede
authors.initials: EK
authors.lastname: Muluneh
authors.affiliation: School of Mathematics, Statistics and Computer Science, University of Kwazulu Natal, South Africa.
authors.forename: Temesgen
authors.initials: T
authors.lastname: Zewotir
authors.affiliation: Central Statistical Authority, Addis Ababa, Ethiopia.
authors.forename: Zerihun
authors.initials: Z
authors.lastname: Bekele
mesh_terms: D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D006801:Humans; D006920:Hygiene; D007223:Infant; D016015:Logistic Models; D008297:Male; D065840:Protective Factors; D011634:Public Health; D012307:Risk Factors; D012424:Rural Population; D012959:Socioeconomic Factors; D014141:Trachoma / Q000453:epidemiology* / Q000209:etiology
keywords: Association; cluster sampling; cumulative logit; design effect; proportional odds