Updating the Read Codes: user-interactive maintenance of a dynamic clinical vocabulary

Abstract

The Read Codes are a hierarchically-arranged controlled clinical vocabulary introduced in the early 1980s and now consisting of three maintained versions of differing complexity. The code sets are dynamic, and are updated quarterly in response to requests from users including clinicians in both primary and secondary care, software suppliers, and advice from a network of specialist healthcare professionals. The codes' continual evolution of content, both across and within versions, highlights tensions between different users and uses of coded clinical data. Internal processes, external interactions and new structural features implemented by the NHS Centre for Coding and Classification (NHSCCC) for user interactive maintenance of the Read Codes are described, and over 2000 items of user feedback episodes received over a 15-month period are analysed.

Figure 1

Different statuses of Version 3 Read Codes within the directed acyclic graph hierarchy.

Figure 2

Scope and overlap of the three versions of the Read Codes.

Figure 3

Software, personnel, and databases involved in Read Code Processing. A series of interactions leading to the generation of Read Code products is illustrated.

Figure 4

Interactions between the NHSCCC and outside agents. These include dialogues, provision of information or products, and membership of advisory panels.

Figure 5

Summary of user feedback types received. Number of feedback items of each type for each version for the fifteen month period to September 1996.