title: A randomized trial of the effectiveness of computer-generated telephone messages in increasing immunization visits among preschool children.
abstract: OBJECTIVE
  To assess the effectiveness of computer-generated telephone reminder and recall messages in increasing preschool immunization visits.
  
  
  METHODS
  Randomized, controlled trial.
  
  
  METHODS
  Fourteen counties in urban and rural Georgia.
  
  
  METHODS
  Children (N = 8002) who were younger than 2 years; had telephone numbers listed in preexisting computerized immunization databases; and were due or late for immunization(s) during the 4-month enrollment period.
  
  
  METHODS
  Households of children were randomized to receive or not receive a general or vaccine-specific computer-generated telephone reminder or recall message the day before the child was due, or immediately after randomization if the child was late.
  
  
  METHODS
  The rates of immunization visits during the 30-day follow-up period.
  
  
  RESULTS
  Of the 4636 children whose households were randomized to receive a message, 1684 (36.3%) visited the health department within 30 days compared with 955 (28.4%) of the 3366 children whose households were not contacted (risk ratio [RR] = 1.28; 95% confidence interval [CI] = 1.20 to 1.37; P < .01). Immunization visits were more frequent (41.1%) among the 3257 children whose households actually received the message (RR = 1.45; 95% CI = 1.36 to 1.56; P < .01). Improvement in immunization visits was similar for general and specific messages, greater for recall than reminder messages, and greatest for children who were late for the third dose of the diphtheria-tetanus-pertussis vaccine and the measles-mumps-rubella vaccine.
  
  
  CONCLUSIONS
  These data suggest a simple and effective way to increase preschool immunization visits, particularly for vaccines associated with the lowest immunization rates.
authors.affiliation: National Immunization Program, Centers for Disease Control and Prevention, Georgia Division of Public Health, Atlanta.
authors.forename: R W
authors.initials: RW
authors.lastname: Linkins
authors.forename: E F
authors.initials: EF
authors.lastname: Dini
authors.forename: G
authors.initials: G
authors.lastname: Watson
authors.forename: P A
authors.initials: PA
authors.lastname: Patriarca
mesh_terms: D002391:Catchment Area, Health; D002662:Child Health Services / Q000458:organization & administration*; D003201:Computers; D005260:Female; D005500:Follow-Up Studies; D005845:Georgia; D006801:Humans; D017589:Immunization Programs / Q000706:statistics & numerical data*; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D010349:Patient Compliance; D017010:Reminder Systems; D012424:Rural Population; D013689:Telephone; D014505:Urban Population