Clinical Decision Support for Immunization (CDSi)

CDSi: Clarity, Consistency, and Computability

Immunization clinical decision support (CDS), more commonly referred to as evaluation and forecasting, is an automated process that determines the recommended immunizations needed for a patient and delivers these recommendations to the healthcare provider. Health Information Systems (HIS) – which can include Health Information Exchanges (HIEs), Immunization Information Systems (IIS) and Electronic Health Records (EHRs) – provide healthcare providers with immunization evaluation and forecasting tools designed to automatically determine the recommended immunizations needed when a patient presents for vaccination. These recommendations are developed by the Advisory Committee on Immunization Practices (ACIP). ACIP is a federal advisory committee responsible for providing expert external advice and guidance to the Director of the Centers for Disease Control and Prevention (CDC) and the Secretary of the U.S. Department of Health and Human Services (DHHS) on use of vaccines and related agents for control of vaccine-preventable disease in the United States. Recommendations include age for vaccine administration, number of doses, dosing interval, and precautions and contraindications.

After ACIP recommendations are published, technical and clinical subject matter experts (SMEs) work to interpret and integrate them into their evaluation and forecasting engines. New ACIP schedule changes are currently communicated only through clinical language, in publications like the Morbidity and Mortality Weekly Report (MMWR) and the Epidemiology and Prevention of Vaccine-Preventable Diseases (“The Pink Book”). The translation of that clinical language into technical logic that can be processed within evaluation and forecasting engines is a time-consuming and complex process that happens mostly independently within the different HIS. Due to the challenge of interpreting clinically-written ACIP recommendations, CDS engine outputs often varied and did not always match the expectations of clinical SMEs.

To this end, the Clinical Decision Support for Immunization (CDSi) project has developed and maintains resources to aid HIS implementers align with the current ACIP recommendations. These resources are summarized in the following introductory materials.

CDSi Mini Guide [8 pages] – The CDSi mini-guide provides a high-level view of the CDSi resources in an easy to read and short format.

CDSi Infographic [1 page] – The CDSi infographic provides a graphical view of the CDSi resources in a 1-page format.

CDSi video [2 mins] - The CDSi video introduces the CDSi resources in a short video.

CDSi Logic Specification and Supporting Data

Clinical Decision Support for Immunization (CDSi): Logic Specification for ACIP Recommendations, Version 4.5 [4.7 MB, 151 pages] Updated February 2024

Supporting Data, Version 4.59 [2 MB] Updated November 2024

The CDSi Logic Specification and Supporting Data provide an implementation-neutral foundation for development and maintenance of CDS engines. They capture ACIP recommendations in an unambiguous manner and improve both the uniform representation of vaccine decision guidelines, as well as the ability to automate vaccine evaluation and forecasting.

The target audience for the Logic Specification and Supporting Data includes business and/or technical implementers of immunization CDS engines. These implementers may support any system with an immunization evaluation and forecasting engine, including but not limited to IIS.

The Logic Specification and the Supporting Data were developed to be as implementation-neutral as possible to support those currently with or without complete evaluation and forecasting engines as they:

• Refine, extend, or develop their implementation;
• Clarify their understanding of immunization rules; and
• Troubleshoot and verify correct implementation of immunization rules.

Test Cases

The CDSi test cases are comprised of two spreadsheets. The first spreadsheet covers routine age-based recommendations for both childhood and adults. The second spreadsheet covers recommendations where an underlying condition (e.g., risk factor) may result in an immunity, contraindication, or indication to vaccinate.

CDSi Test Cases – Healthy Childhood and Adult, version 4.40 – Updated November 2024

CDSi Test Cases – Underlying Conditions, version 4.5 – Updated May 2024

User Support

Please email any questions to: IISinfo@cdc.gov.