title: Do changes in socio-demographic characteristics impact up-to-date immunization status between 3 and 24 months of age? A prospective study among an inner-city birth cohort in the United States.
abstract: Low-income child populations remain under-vaccinated. Our objective was to determine differences in the relative importance of maternal health literacy and socio-demographic characteristics that often change during early childhood on up-to-date (UTD) immunization status among a low-income population.
  
  
  
  We performed secondary data analysis of a longitudinal prospective cohort study of 744 Medicaid-eligible mother-infant dyads recruited at the time of the infant's birth from an inner-city hospital in the United States and surveyed every 6 months for 24 months. Our primary outcome was infant UTD status at 24 months abstracted from a citywide registry. We assessed maternal health literacy with the Test of Functional Health Literacy in Adults (short version). We collected socio-demographic information via surveys at birth and every 6 months. We compared predictors of UTD status at 3, 7, and 24 months.
  
  
  
  The cohort consisted of primarily African-American (81.5%) mothers with adequate health literacy (73.9%). Immunizations were UTD among 56.7% of infants at 24 months of age. Maternal health literacy was not a significant predictor of UTD immunization status. Instead, adjusted results showed that significant predictors of not-UTD status at 24 months were lack of a consistent health care location or "medical home" (OR 0.17, 95%CI 0.18-0.37), inadequate prenatal care (OR 0.48, 95%CI 0.25-0.95), and prior not-UTD status (OR 0.31, 95%CI 0.20-0.47). Notably, all upper confidence limits are less than 1.0 for these variables. Health care location type (e.g., hospital-affiliate, community-based, none) was a significant predictor of vaccine status at age 3 months, 7 months, and 24 months.
  
  
  
  Investing in efforts to support early establishment of a medical home to obtain comprehensive coordinated preventive care, including providing recommended vaccines on schedule, is a prudent strategy to improve vaccination status at the population level.
authors.affiliation: a Division of Primary Care Pediatrics , State University of New York at Stony Brook , Stony Brook , NY , USA.
authors.forename: Susmita
authors.initials: S
authors.lastname: Pati
authors.affiliation: a Division of Primary Care Pediatrics , State University of New York at Stony Brook , Stony Brook , NY , USA.
authors.forename: Jiayu
authors.initials: J
authors.lastname: Huang
authors.affiliation: a Division of Primary Care Pediatrics , State University of New York at Stony Brook , Stony Brook , NY , USA.
authors.forename: Angie
authors.initials: A
authors.lastname: Wong
authors.affiliation: b Division of General Pediatrics , The Children's Hospital of Philadelphia , Philadelphia , PA , USA.
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Baba
authors.affiliation: b Division of General Pediatrics , The Children's Hospital of Philadelphia , Philadelphia , PA , USA.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Ostapenko
authors.affiliation: b Division of General Pediatrics , The Children's Hospital of Philadelphia , Philadelphia , PA , USA.|c Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania , Philadelphia , PA , USA.|d Leonard Davis Institute of Health Economics, University of Pennsylvania , Philadelphia , PA , USA.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Fiks
authors.affiliation: e Center for Clinical and Translational Science, Children's National Health System , Washington , DC , USA.
authors.forename: Avital
authors.initials: A
authors.lastname: Cnaan
mesh_terms: D001741:Black or African American; D002675:Child, Preschool; D015331:Cohort Studies; D003710:Demography; D005191:Family Characteristics; D057220:Health Literacy; D006801:Humans; D007114:Immunization / Q000706:statistics & numerical data*; D017589:Immunization Programs / Q000706:statistics & numerical data*; D007223:Infant; D008137:Longitudinal Studies; D000068097:Maternal Health; D008484:Medicaid; D009035:Mothers; D011203:Poverty; D011446:Prospective Studies; D012959:Socioeconomic Factors; D014481:United States; D014505:Urban Population / Q000706:statistics & numerical data
keywords: Cohort Studies; immunizations; pediatric care; vaccinations