Which coding system for therapeutic information in evidence-based medicine.

The coding of information in the computer representation of clinical trials is essential both for the rationalisation of the activities involved in the production of therapeutic information for evidence-based decision support and for the integration of the messages produced by these activities with clinical information and electronic patient record systems. There is no standard coding system available, however, so building on existing evaluations, we performed a simple semi-quantitative evaluation of ICD-10, CDAM, MEDDRA, MESH, READ, SNOMED and UMLS to provide objective criteria for the choice of a coding system. Inclusion and exclusion criteria for four clinical trials recorded in TriSum constituted the corpus of evaluation texts. Criteria included coding coverage, size, integration and language coverage. The results of the comparison lead us to choose SNOMED as the most appropriate coding system for our needs. The absence of a European Medical Language System project is observed, as is the need for combinatorial as opposed to enumerative systems.