Metrics: Complete

The code system can represent any vaccination that was given at anytime in the past, anywhere in the world, and to any person currently living.

A universally applicable system ensures that any individual's vaccination history can be integrated, regardless of the origin.

The total number of codes needed to represent all existing legacy vaccines, plus any vaccine trail representing a class of vaccines rather than an actual product, is not known ex ante.

The most comprehensive among the existing code systems, NUVA (enriched continuously over the last decade and field proven at a large scale) currently includes 917 codes. Based on current trends, we can make an educated guess that the total number should be in the range of 1200 codes. We will use this value as the basis for the exhaustiveness indicator, as the percentage of the 1200 codes covered by a given code system.

If NUVA continues to be updated with codes to represent all vaccine concepts currently coded, then it could be used as a baseline for determining if a code set is complete. To do this NUVA would need to identify a minimum set of codes, from the NUVA code system, which a complete vaccine code system should have a concept for. The concept in the target code system should be such that it can be mapped directly and unambiguously to a NUVA code and that NUVA code can be mapped back directly and unambiguously to that same code. Thus demonstrating that this code system has a direct one-to-one equivalent for the concept in NUVA. The measure would calculate the total number of NUVA minimum set codes that can be one-to-one represented in the code set being measured.

FKa - I am not sure about the one-to-one mapping back from NUVA to the original code. For example, code systems that represent a substance and its packaging can be complete, while there will be several such codes for a given NUVA code (since NUVA does not take into account the packaging, that is useless for tracking received vaccines).

Measure = [Total number of target code set values that can be mapped directly one-for-one to NUVA code in the denominator] / [Number of NUVA codes that are necessary for supporting a complete and accurate immunization history for any patient living today in any part of the world.]

FKa - When NUVA incorporates a mapping for an external code system, it is by construction a one-to-one from the original code to the NUVA code. Either it was identified that it matched a preexisting NUVA concept (e.g. the national pharmaceutical code for a vaccine that is already known from other countries). So the numerator corresponds to the number of codes in the code system.