The impact of computer-generated messages on childhood immunization coverage

Introduction: Recent evaluations of computer-generated reminder/recall mess ages have suggested that they are an inexpensive, labor-saving method of im proving office visitation rates of childhood immunization providers. This s tudy assesses the sustained impact of computer-generated messages on immuni zation coverage during the first two years of life. Design: Randomized, controlled trial. Setting: County health department in the Denver metropolitan area. Study Participants: Children ( n 1227) 60 to 90 days of age who had receive d the first dose of diphtheria-tetanus-pertussis (DTP) and/or poliovirus va ccines. Intervention: Households of children were randomized into four groups to re ceive: telephone messages followed by letters (Group A); telephone messages alone (Croup B); letters only (Group C); or no notification (Group D). Hou seholds in the intervention groups (A, B, and C) received up to five comput er-generated telephone messages and/or up to four letters each time their c hildren became due for immunization(s). Main Outcome Measure: Immunization series completion at 24 months of age. Results: Children whose families were randomized to receive any of the inte rventions were 21% more likely to have completed the immunization series by 24 months of age than were children randomized into the control group (49. 2% vs 40.9%; RR [rate ratio] = .21; CI [confidence interval] = 1.01, 1.44). While not statistically significant, children in Group A were 23% more lik ely to complete their immunization series by 24 months of age than those in the control group (50.2% vs 40.9%; RR = 1.23; CI = 1.00, 1.52). No differe nces were detected among the intervention groups. The costs per additional child completing the series by 24 months of age in Group A was $226 ($79 af ter start-up costs were discounted). Conclusion: Computer-generated contacts, either by phone or by mail (or bot h combined), used each time vaccines become due, are efficacious in increas ing immunization coverage of children under 2 years of age. (C) 2000 Americ an Journal of Preventive Medicine.