title: Lower respiratory illness in infants and low socioeconomic status.
abstract: OBJECTIVE
  Infants from families of low socioeconomic status are said to suffer higher rates of lower respiratory illness, but this assertion has not been carefully examined.
  
  
  METHODS
  We studied the frequency and determinants of lower respiratory illness in infants of different socioeconomic status (n = 393) by analyzing data from a community-based cohort study of respiratory illness during the first year of life in central North Carolina.
  
  
  RESULTS
  The incidence of lower respiratory illness was 1.41 in the low socioeconomic group, 1.26 in the middle group, and 0.67 in the high group. The prevalence of persistent respiratory symptoms was 39% in infants in the low socioeconomic group, 24% in infants in the middle group, and 14% in infants in the high group. The odds of persistent respiratory symptoms in infants of low and middle socioeconomic status were reduced after controlling for environmental risk factors for lower respiratory illness. Enrollment in day care was associated with an increased risk of persistent symptoms among infants of high but not low socioeconomic status.
  
  
  CONCLUSIONS
  Infants of low socioeconomic status are at increased risk of persistent respiratory symptoms. This risk can be partly attributed to environmental exposures, most of which could be changed.
authors.affiliation: Department of Pediatrics, University of North Carolina, Chapel Hill 27599-7490.
authors.forename: P A
authors.initials: PA
authors.lastname: Margolis
authors.forename: R A
authors.initials: RA
authors.lastname: Greenberg
authors.forename: L L
authors.initials: LL
authors.lastname: Keyes
authors.forename: L M
authors.initials: LM
authors.lastname: LaVange
authors.forename: R S
authors.initials: RS
authors.lastname: Chapman
authors.forename: F W
authors.initials: FW
authors.lastname: Denny
authors.forename: K E
authors.initials: KE
authors.lastname: Bauman
authors.forename: B W
authors.initials: BW
authors.lastname: Boat
mesh_terms: D000208:Acute Disease; D002656:Child Day Care Centers; D002908:Chronic Disease; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D009657:North Carolina / Q000453:epidemiology; D011203:Poverty; D015995:Prevalence; D012135:Respiratory Sounds; D012140:Respiratory Tract Diseases / Q000453:epidemiology*; D012307:Risk Factors; D012923:Social Class