title: Associations of preterm births with child health and development: Japanese population-based study.
abstract: OBJECTIVE
  To examine associations between the duration of gestation and health and development outcomes at 2.5 years and 5.5 years using a Japanese population-based longitudinal survey (n = 47 015).
  
  
  METHODS
  Hospitalization was used as an indicator of physical health, and responses to questions about age-appropriate behaviors were used as an indicator of behavioral development. We conducted logistic regression analyses controlling for a set of neonatal and family factors. We also estimated population-attributable fractions.
  
  
  RESULTS
  We observed a steady increase toward shorter duration of gestation in the risk of hospitalizations at age 2.5 years and 5.5 years and developmental delays at 2.5 years (Plinear trend < .001 for all outcomes). We found associations only between extremely preterm birth and delayed behavioral development at age 5.5 years.
  
  
  CONCLUSIONS
  There is a linear relationship between shorter duration of gestation and increased risk of later health and developmental problems. In line with Rose's "population paradox," the population-attributable risks for these problems are greater for moderately preterm infants compared with extremely preterm infants.
authors: Department of Public Health and Public Policy, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan. Electronic address: goose@hiroshima-u.ac.jp.
authors: Tsuguhiko
authors: T
authors: Kato
authors: Takashi
authors: T
authors: Yorifuji
authors: Sachiko
authors: S
authors: Inoue
authors: Michiyo
authors: M
authors: Yamakawa
authors: Hiroyuki
authors: H
authors: Doi
authors: Ichiro
authors: I
authors: Kawachi
mesh_terms: D002657:Child Development; D002669:Child Welfare; D002675:Child, Preschool; D005260:Female; D006306:Health Surveys; D006801:Humans; D007234:Infant, Premature; D007564:Japan; D008137:Longitudinal Studies; D008297:Male; D047928:Premature Birth; D011446:Prospective Studies
keywords: MHLW; Ministry of Health, Labour, and Welfare; PAF; Population-attributable fraction