title: Age-specific strategies for immunization reminders and recalls: a registry-based randomized trial.
abstract: BACKGROUND
  Although previous studies have found reminder/recall to be effective in increasing immunization rates, little guidance exists regarding the specific ages at which it is optimal to send reminder/recall notices.
  
  
  OBJECTIVE
  To assess the relative effectiveness of centralized reminder/recall strategies targeting age-specific vaccination milestones among children in urban areas during June 2008-June 2009.
  
  
  METHODS
  Three reminder/recall strategies used capabilities of the Michigan Care Improvement Registry (MCIR), a statewide immunization information system: a 7-month recall strategy, a 12-month reminder strategy, and a 19-month recall strategy. Eligible children were randomized to notification (intervention) or no notification groups (control). Primary study outcomes included MCIR-recorded immunization activity (administration of ≥1 new dose, entry of ≥1 historic dose, entry of immunization waiver) within 60 days following each notification cycle.
  
  
  RESULTS
  A total of 10,175 children were included: 2,072 for the 7-month recall, 3,502 for the 12-month reminder, and 4,601 for the 19-month recall. Immunization activity was similar between notification versus no notification groups at both 7 and 12 months. Significantly more 19-month-old children in the recall group (26%) had immunization activity compared to their counterparts who did not receive a recall notification (19%).
  
  
  CONCLUSIONS
  Although recall notifications can positively affect immunization activity, the effect may vary by targeted age group. Many 7- and 12-month-olds had immunization activity following reminder/recall; however, levels of activity were similar irrespective of notification, suggesting that these groups were likely to receive medical care or immunization services without prompting.
authors.affiliation: Child Health Evaluation and Research Unit, Division of General Pediatrics, University of Michigan, Ann Arbor, Michigan. Electronic address: kjd@med.umich.edu.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Dombkowski
authors.affiliation: Child Health Evaluation and Research Unit, Division of General Pediatrics, University of Michigan, Ann Arbor, Michigan.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Costello
authors.affiliation: Child Health Evaluation and Research Unit, Division of General Pediatrics, University of Michigan, Ann Arbor, Michigan.
authors.forename: Laura B
authors.initials: LB
authors.lastname: Harrington
authors.affiliation: Child Health Evaluation and Research Unit, Division of General Pediatrics, University of Michigan, Ann Arbor, Michigan.
authors.forename: Shiming
authors.initials: S
authors.lastname: Dong
authors.affiliation: National Center for Immunization and Respiratory Diseases, the CDC, Atlanta, Georgia.
authors.forename: Maureen
authors.initials: M
authors.lastname: Kolasa
authors.affiliation: National Center for Immunization and Respiratory Diseases, the CDC, Atlanta, Georgia.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Clark
mesh_terms: D000367:Age Factors; D006801:Humans; D007114:Immunization / Q000706:statistics & numerical data*; D017589:Immunization Programs / Q000379:methods*; D007223:Infant; D008824:Michigan; D012042:Registries; D017010:Reminder Systems; D013997:Time Factors; D014505:Urban Population; D014611:Vaccination / Q000706:statistics & numerical data*