Figure 2, above, [click here for larger version] further explicates nursing vocabulary needs from the point of care through universal levels. This figure points out that, at the point of care, nursing needs several vocabularies to communicate relevant information gathered during the patient encounter. These point of service-level vocabularies are used for documentation purposes to translate information into patient records; in turn, information from these records is extracted electronically and communicated to the network level. At this level, vocabularies are aggregated to higher level network classifications. This aggregation of terms into network classifications decreases the likelihood of errors in interpretation that may result from variability in vocabularies, terms, and definitions used at the point of service.

If all the nurses in a network such as Kaiser Permanente used different vocabularies and classifications, the costs and burden of linking information, while technically feasible, will be more time consuming and costly. The convergence of data elements or records from the network level into meaningful national or international data repositories at the universal level will require, for simplicity, a unicode or single taxonomy. Further, with comparisons between regions of a country, which are based on different definitions of terms, different vocabularies and different classifications, the likelihood of error in definition, interpretation, and aggregation would be more common.

As an example, to clarify these relationships, consider the nurse providing care in schools. This nurse uses terms and phrases that convey relevant patient level information unique to the population. Although some terms and phrases used obviously would cross over into other points of care, such as primary care, certain vocabulary would be necessary for understanding particular situations unique to the school. Information gathered by the nurse at the school point of service would be communicated through one or more systems to the network level. At this level, information would be classified into network classifications, and subsequently channeled to data repositories at the universal level. When, and if, nursing has a universal taxonomy, it is possible that even the point of care and network vocabularies and classifications could converge with the universal level taxonomy.

Table 3.
Examples of changes or consistency across levels of use.
Level of Use	Different	Similar
Point of care	ear pain	Stress incontinence
Network	ear infection, left ear	Stress incontinence
Universal	Otitis Media, without effusion	Stress incontinence

An example of a concept taken from the point of care to the reference and finally to the universal levels is in Table 3. The first example demonstrates that a vocabulary can change from point of care to network to universal levels for a condition such as ear pain. The second example shows a consistency or a unicode that can be and is being used at all three levels to describe stress incontinence.