The costs of registry-based immunization interventions

BACKGROUND: Part of the payoff of immunization registries may be to lower costs of immunization intervention. However- registry-based intervention costs have not been evaluated in a community setting. METHODS: The purpose of this study was to prospectively measure the cost of three equally effective registry-based interventions- evaluate how the size of the targeted population affects cost estimates- and compare these results with previously reported studies. A total of 3050 children aged <12 months were randomized to one of four study arms: (1) computer-generated telephone messages (autodialer)- (2) outreach worker- (3) autodialer with outreach worker backup- or (4) usual care. The cost data collected included capital equipment- supplies- travel- and personnel. RESULTS: Monthly costs of the three registry-based intervention types were (1) autodialer- $1.34 per child/ (2) outreach worker- $1.87 per child- and (3) combination- $2.76 per child. Personnel costs represented the majority of incremental costs for all three interventions. Increasing the number of children targeted sharply decreased the cost per child for the autodialer but had only a modest effect on outreach costs. The monthly costs for outreach were substantially lower than previously reported for nonregistry-based interventions in part because of differences in the number of children who were followed up. Monthly costs for the autodialer intervention were slightly higher than previously reported- but several published studies excluded important costs. CONCLUSIONS: By facilitating the management of a larger cohort of children- some registry-based immunization interventions appear to be less costly than nonregistry interventions. Further work is needed to establish whether registry maintenance costs may be recouped in part by these savings.