Inter-terminology mapping of nursing problems.

Abstract

The purpose of this study was to determine the degree of overlap between the International Classification for Nursing Practice (ICNP®) and the Systematized Nomenclature of Medicine-Clinical Terms (SNOMED-CT), with a specific focus on nursing problems, as a first step towards harmonization of content between the two terminologies. Work within this study was divided across two ICNP subsets. The first subset (n=238) was made up of ICNP diagnosis/outcome concepts that had been included in previous experimental mapping activities with Clinical Care Classification (CCC) and NANDA-International (NANDA-I). These ICNP concepts and their equivalent concepts within CCC and NANDA-I were used within the Unified Medical Language System (UMLS) framework to derive automatically candidate mappings to SNOMED-CT for validation by two reviewers. The second subset (n=565) included all other ICNP diagnosis/outcome concepts plus those concepts from the first subset where the candidate mappings were rejected. Mappings from the second subset to SNOMED-CT were manually identified independently by the same two reviewers. Differences between the reviewers were resolved through discussion. The observed agreement between the two reviewers was calculated along with the inter-rater reliability using Cohen's Kappa (κ). For the first semi-automated mapping, according to the two reviewers the great majority of ICNP concepts (91.6%) correctly mapped to SNOMED-CT in UMLS. There was a good level of agreement between the reviewers in this part of the exercise (κ=0.7). For the second manual mapping, nearly two-thirds of ICNP concepts (61.4%) could not be mapped to any SNOMED-CT concept. There was only a moderate level of agreement between the reviewers (κ=0.45). While most of the mappings were one-to-one mappings, there were ambiguities in both terminologies which led to difficulties. The absence of mappings was due to a large extent to differences in content coverage, although lexical variations and semantic differences also played a part. This study demonstrated a degree of overlap between ICNP and SNOMED-CT; it also identified significant differences in content coverage. The results from the semi-automated mapping were encouraging, particularly for 'older' ICNP content. The results from the manual mapping were less favorable suggesting a need for further enhancement of both terminologies, content development within SNOMED-CT and further research on mechanisms for harmonization.