Service-Oriented Architecture: Immunization Information System Case Studies

Background: Immunization information systems (IIS) can be costly to maintain or replace. Service-oriented architectures (SOA) have provided a way for these systems to remain viable and responsive to increasing demands for information and analysis. This paper offers two case studies of production IIS in different jurisdictions and the strategies used with SOA to extend system life and to enable new and important features.

Setting: IIS in New York City and Rhode Island were enhanced through SOA capabilities to offer additional functionality with little disruption to ongoing operations and at lower long-term cost.

Population: N/A

Project Description: In both case study examples, an SOA approach was selected because it provided the best investment: a modular design which required the least modification to the existing, production system while retaining the greatest degree of flexibility for potential replacement or augmentation of the new functionality if requirements, standards, or technologies change. The New York City Citywide Immunization Registry (CIR) provides a consolidated database of all childhood and adolescent immunizations administered to City residents. Two services were developed: The first service allows an electronic health record system (EHR-S) to query the CIR and receive in response the immunization history and clinical decision support for the patient; the second service allows the EHR-S to report new immunizations to the CIR. In Rhode Island, KIDSNET is a computerized registry used to track children’s use of preventive health services. After studying and testing several alternatives, Rhode Island decided to integrate as a service an immunization algorithm from another state with minimal modification to KIDSNET itself.

Results/Lessons Learned: Service-oriented architecture has moved into the mainstream of technical development strategies. This presentation demonstrates that it can be a useful tool to enable rich functionality within existing public health systems, while minimizing the cost and time to deploy these new features.