Issues in accommodating national changes and local variation in a computer-based guideline for childhood immunization and in related knowledge maintenance tools.

As clinical practice guidelines are increasingly implemented in computer-based form, a major challenge will be to maintain their domain knowledge as new national recommendations are developed and as local customization is required. This maintenance may also need to be performed for any computer-based tools developed to help in the guideline knowledge maintenance process itself. This paper uses the domain of childhood immunization to explore certain issues involved. It describes 1) two recent changes to the national recommendations dealing with the DTP and Polio vaccine series, and 2) several customizations requested by the immunization registries of the State of Oregon and the US Indian Health Service. It then describes how these guideline practice variations are currently handled in three computer-based tools, IMM/Serve, IMM/Def, and IMM/Test. Finally, it discusses how the use of these tools can provide one approach to characterizing the complexity of guideline variations.