The impact of reminder-recall interventions on low vaccination coverage in an inner-city population

BACKGROUND: Reminder-recall interventions have improved immunization rates in numerous studies. OBJECTIVE: To evaluate the impact of large-scale- registry-based reminder-recall interventions on low immunization rates in an inner-city population. DESIGN: Randomized- controlled- effectiveness trial. SETTING: Fulton County- Georgia. PARTICIPANTS: A total of 3050 children (76% black- 14% Hispanic- 7% white- and 3% other or unknown/ median age- 9 months/ range- 1-14 months) identified in an immunization registry as receiving health care in the public sector. INTERVENTIONS: Each child was randomly assigned to 1 of 4 groups: control (usual care)- autodialer (automated telephone or mail reminder recall)- outreach (in-person telephone- mail- or home visit recall)- and combination (autodialer with outreach backup). Interventions continued until the child reached 24 months of age. MAIN OUTCOME MEASURE: Completion by the age of 24 months of the 4-3-1-3 vaccination series based on intention-to-treat analysis. RESULTS: A total of 260 (34%) of the 763 patients in the control group- 306 (40%) of the 763 in the autodialer group- 284 (37%) of the 760 in the outreach group- and 293 (38%) of 764 in the combination group completed the vaccination series. CONCLUSION: Large-scale- registry-based reminder-recall interventions produced only small improvements in low immunization rates of an inner-city population.