title: Facilitating pre-operative assessment guidelines representation using SNOMED CT.
abstract: OBJECTIVE
  To investigate whether SNOMED CT covers the terms used in pre-operative assessment guidelines, and if necessary, how the measured content coverage can be improved.
  
  
  METHODS
  Pre-operative assessment guidelines were retrieved from the websites of (inter)national anesthesia-related societies. The recommendations in the guidelines were rewritten to "IF condition THEN action" statements to facilitate data extraction. Terms were extracted from the IF-THEN statements and mapped to SNOMED CT. Content coverage was measured by using three scores: no match, partial match and complete match. Non-covered concepts were evaluated against the SNOMED CT editorial documentation.
  
  
  RESULTS
  From 6 guidelines, 133 terms were extracted, of which 71% (n=94) completely matched with SNOMED CT concepts. Disregarding the vague concepts in the included guidelines SNOMED CT's content coverage was 89%. Of the 39 non-completely covered concepts, 69% violated at least one of SNOMED CT's editorial principles or rules. These concepts were categorized based on four categories: non-reproducibility, classification-derived phrases, numeric ranges, and procedures categorized by complexity.
  
  
  CONCLUSIONS
  Guidelines include vague terms that cannot be well supported by terminological systems thereby hampering guideline-based decision support systems. This vagueness reduces the content coverage of SNOMED CT in representing concepts used in the pre-operative assessment guidelines. Formalization of the guidelines using SNOMED CT is feasible but to optimize this, first the vagueness of some guideline concepts should be resolved and a few currently missing but relevant concepts should be added to SNOMED CT.
authors.affiliation: Dept. of Medical Informatics, Academic Medical Center, University of Amsterdam, The Netherlands. l.ahmadian@amc.uva.nl
authors.forename: Leila
authors.initials: L
authors.lastname: Ahmadian
authors.forename: Ronald
authors.initials: R
authors.lastname: Cornet
authors.forename: Nicolette F
authors.initials: NF
authors.lastname: de Keizer
mesh_terms: D057225:Data Mining / Q000379:methods; D016208:Databases, Factual; D017410:Practice Guidelines as Topic; D057234:Preoperative Period; D039061:Systematized Nomenclature of Medicine; D009626:Terminology as Topic