Evaluation of negation phrases in narrative clinical reports.

@article{citeulike:239653, abstract = {OBJECTIVE: Automatically identifying findings or diseases described in clinical textual reports requires determining whether clinical observations are present or absent. We evaluate the use of negation phrases and the frequency of negation in free-text clinical reports. METHODS: A simple negation algorithm was applied to ten types of clinical reports (n=42,160) dictated during July 2000. We counted how often each of 66 negation phrases was used to mark a clinical observation as absent. Physicians read a random sample of 400 sentences, and precision was calculated for the negation phrases. We measured what proportion of clinical observations were marked as absent. RESULTS: The negation algorithm was triggered by sixty negation phrases with just seven of the phrases accounting for 90\% of the negations. The negation phrases received an overall precision of 97\%, with "not" earning the lowest precision of 63\%. Between 39\% and 83\% of all clinical observations were identified as absent by the negation algorithm, depending on the type of report analyzed. The most frequently used clinical observations were negated the majority of the time. CONCLUSION: Because clinical observations in textual patient records are frequently negated, identifying accurate negation phrases is important to any system processing these reports.}, address = {Center for Biomedical Informatics, University of Pittsburgh, Pittsburgh, PA, USA.}, author = {Chapman, W. W. and Bridewell, W. and Hanbury, P. and Cooper, G. F. and Buchanan, B. G. }, citeulike-article-id = {239653}, issn = {1531-605X}, journal = {Proc AMIA Symp}, keywords = {clinical, natural\_language\_processing, negation\_detection, nlp}, pages = {105--109}, posted-at = {2007-10-24 13:59:12}, priority = {0}, title = {Evaluation of negation phrases in narrative clinical reports.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/11825163}, year = {2001} }

TY - JOUR ID - citeulike:239653 L3 - citeulike-article-id:239653 TI - Evaluation of negation phrases in narrative clinical reports. JF - Proc AMIA Symp SP - 105 EP - 109 AD - Center for Biomedical Informatics, University of Pittsburgh, Pittsburgh, PA, USA. SN - 1531-605X N2 - OBJECTIVE: Automatically identifying findings or diseases described in clinical textual reports requires determining whether clinical observations are present or absent. We evaluate the use of negation phrases and the frequency of negation in free-text clinical reports. METHODS: A simple negation algorithm was applied to ten types of clinical reports (n=42,160) dictated during July 2000. We counted how often each of 66 negation phrases was used to mark a clinical observation as absent. Physicians read a random sample of 400 sentences, and precision was calculated for the negation phrases. We measured what proportion of clinical observations were marked as absent. RESULTS: The negation algorithm was triggered by sixty negation phrases with just seven of the phrases accounting for 90% of the negations. The negation phrases received an overall precision of 97%, with "not" earning the lowest precision of 63%. Between 39% and 83% of all clinical observations were identified as absent by the negation algorithm, depending on the type of report analyzed. The most frequently used clinical observations were negated the majority of the time. CONCLUSION: Because clinical observations in textual patient records are frequently negated, identifying accurate negation phrases is important to any system processing these reports. KW - clinical KW - natural_language_processing KW - negation_detection KW - nlp AU - Chapman, WW AU - Bridewell, W AU - Hanbury, P AU - Cooper, GF AU - Buchanan, BG PY - 2001/// UR - http://view.ncbi.nlm.nih.gov/pubmed/11825163 ER -