The Certainty-Agreement diagram: comparing the functionality of coding schemes in primary care clinical information systems.

Despite enormous investment of effort and resources there are few formal comparative evaluations between different coding schemes. We have recently described a methodology of a randomised crossover trial comparing the performance of Clinical Terms Version 3 (CTV3) and Read Codes 5 Byte set (RC5B) coding schemes in General Practice. 1 This study looked at the comparative performance of the two coding schemes by 10 general practitioners using a total of 995 concepts extracted from clinical records. This paper describes the use of the Certainty-Agreement diagram in providing a graphical representation of comparative functionality.

RCT Entities:   Population Interventions Outcomes