title: Contextual determinants of neonatal mortality using two analysis methods, Rio Grande do Sul, Brazil.
abstract: OBJECTIVE
  To analyze neonatal mortality determinants using multilevel logistic regression and classic hierarchical models.
  
  
  METHODS
  Cohort study including 138,407 live births with birth certificates and 1,134 neonatal deaths recorded in 2003, in the state of Rio Grande do Sul, Southern Brazil. The Information System on Live Births and mortality records were linked for gathering information on individual-level exposures. Sociodemographic data and information on the pregnancy, childbirth care and characteristics of the children at birth were collected. The associated factors were estimated and compared by traditional and multilevel logistic regression analysis.
  
  
  RESULTS
  The neonatal mortality rate was 8.19 deaths per 1,000 live births. Low birth weight, 1- and 5-minute Apgar score below eight, congenital malformation, pre-term birth and previous fetal loss were associated with neonatal death in the traditional model. Elective cesarean section had a protective effect. Previous fetal loss did not remain significant in the multilevel model, but the inclusion of a contextual variable (poverty rate) showed that 15% of neonatal mortality variation can be explained by varying poverty rates in the microregions.
  
  
  CONCLUSIONS
  The use of multilevel models showed a small effect of contextual determinants on the neonatal mortality rate. There was found a positive association with the poverty rate in the general model, and the proportion of households with water supply among preterm newborns.
authors.affiliation: Departamento de Estatística, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil. rrzanini@terra.com.br
authors.forename: Roselaine Ruviaro
authors.initials: RR
authors.lastname: Zanini
authors.forename: Anaelena Bragança de
authors.initials: AB
authors.lastname: Moraes
authors.forename: Elsa Regina Justo
authors.initials: ER
authors.lastname: Giugliani
authors.forename: João
authors.initials: J
authors.lastname: Riboldi
mesh_terms: D001034:Apgar Score; D001724:Birth Weight / Q000502:physiology; D001938:Brazil / Q000453:epidemiology; D002423:Cause of Death; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007234:Infant, Premature; D050498:Live Birth / Q000453:epidemiology; D008297:Male; D015233:Models, Statistical; D009035:Mothers / Q000706:statistics & numerical data; D011203:Poverty / Q000706:statistics & numerical data; D011247:Pregnancy; D012307:Risk Factors; D014881:Water Supply