title: Respiratory syncytial virus immunoprophylaxis in high-risk infants and development of childhood asthma.
abstract: Respiratory syncytial virus (RSV) lower respiratory tract infection is implicated in asthma development. RSV immunoprophylaxis during infancy is efficacious in preventing RSV-related hospitalizations and has been associated with decreased wheezing in the first years of life.
  
  
  
  We investigated whether greater adherence to immunoprophylaxis in infants at high risk for severe RSV would be associated with decreased childhood asthma.
  
  
  
  We conducted a retrospective cohort investigation including children born from 1996-2003 who were enrolled in Kaiser Permanente Northern California or Tennessee Medicaid and eligible to receive RSV immunoprophylaxis. Asthma was defined at 4.5 to 6 years of age by using asthma-specific health care visits and medication fills. We classified children into immunoprophylaxis eligibility groups and calculated adherence (percentage receipt of recommended doses). We used a set of statistical strategies (multivariable logistic regression and propensity score [PS]-adjusted and PS-matched analyses) to overcome confounding by medical complexity because infants with higher adherence (≥70%) have higher prevalence of chronic lung disease, lower birth weight, and longer nursery stays.
  
  
  
  By using multivariable logistic regression and PS-adjusted models in the combined group, higher adherence to RSV immunoprophylaxis was not associated with decreased asthma. However, in PS-matched analysis, treated children with 70% or greater adherence had decreased odds of asthma compared with those with 20% or less adherence (odds ratio, 0.62; 95% CI, 0.50-0.78).
  
  
  
  This investigation of RSV immunoprophylaxis in high-risk children primarily found nonsignificant associations on prevention of asthma in specific preterm groups. Our findings highlight the need for larger studies and prospective cohorts and provide estimates of potential preventive effect sizes in high-risk children.
authors.affiliation: Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tenn; Center for Asthma and Environmental Health Sciences Research, Vanderbilt University School of Medicine, Nashville, Tenn.
authors.forename: Kecia N
authors.initials: KN
authors.lastname: Carroll
authors.affiliation: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tenn; Center for Asthma and Environmental Health Sciences Research, Vanderbilt University School of Medicine, Nashville, Tenn.
authors.forename: Tebeb
authors.initials: T
authors.lastname: Gebretsadik
authors.affiliation: Kaiser Permanente Medical Care Program, Perinatal Research Unit, Division of Research, Oakland, Calif; Kaiser Permanente, Perinatal Research Unit, Division of Research, Oakland, Calif; Department of Inpatient Pediatrics, Kaiser Permanente Medical Center, Walnut Creek, Calif.
authors.forename: Gabriel J
authors.initials: GJ
authors.lastname: Escobar
authors.affiliation: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tenn; Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tenn; Center for Asthma and Environmental Health Sciences Research, Vanderbilt University School of Medicine, Nashville, Tenn.
authors.forename: Pingsheng
authors.initials: P
authors.lastname: Wu
authors.affiliation: Kaiser Permanente, Perinatal Research Unit, Division of Research, Oakland, Calif.
authors.forename: Sherian Xu
authors.initials: SX
authors.lastname: Li
authors.affiliation: Kaiser Permanente, Perinatal Research Unit, Division of Research, Oakland, Calif.
authors.forename: Eileen M
authors.initials: EM
authors.lastname: Walsh
authors.affiliation: Department of Health Policy, Vanderbilt University School of Medicine, Nashville, Tenn; Center for Asthma and Environmental Health Sciences Research, Vanderbilt University School of Medicine, Nashville, Tenn.
authors.forename: Ed
authors.initials: E
authors.lastname: Mitchel
authors.affiliation: Center for Asthma and Environmental Health Sciences Research, Vanderbilt University School of Medicine, Nashville, Tenn; Brigham Young University, Provo, Utah.
authors.forename: Chantel D
authors.initials: CD
authors.lastname: Sloan
authors.affiliation: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tenn; Center for Asthma and Environmental Health Sciences Research, Vanderbilt University School of Medicine, Nashville, Tenn.
authors.forename: William D
authors.initials: WD
authors.lastname: Dupont
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tenn; Center for Asthma and Environmental Health Sciences Research, Vanderbilt University School of Medicine, Nashville, Tenn. Electronic address: tina.hartert@vanderbilt.edu.
authors.forename: Tina V
authors.initials: TV
authors.lastname: Hartert
mesh_terms: D001249:Asthma / Q000453:epidemiology / Q000517:prevention & control*; D002140:California / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007114:Immunization; D007223:Infant; D008297:Male; D008484:Medicaid; D016017:Odds Ratio; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology / Q000517:prevention & control*; D018113:Respiratory Syncytial Virus, Human; D012307:Risk Factors; D013714:Tennessee / Q000453:epidemiology; D014481:United States
keywords: Respiratory syncytial virus; asthma; bronchiolitis; lower respiratory tract infection; palivizumab; primary prevention; respiratory syncytial virus immunoprophylaxis; wheezing