Rewriting and suppressing UMLS terms for improved biomedical term identification

Table 3 Rewritten or suppressed terms and concepts found in the corpus.

Rule	Terms in corpus (all)	Terms in corpus (distinct)	Concepts in corpus (distinct)
Original	3,992,662,340	651,268	397,414
Rewrite rules
Syntactic inversion	529,058	12,433	11,291
Possessives	34,211	1,134	946
Short/long form	305,541	216	182
Angular brackets	30,124	743	731
Semantic type	218,838	259	259
Begin parentheses	523	26	25
End parentheses	8,916,764	4,776	4,494
Begin brackets	176,791	274	251
End brackets	65,873	241	236
*Suppression rules*
Dosages	109,246	5,014	4,885
Short token	1,906,901,846	1009	945
At-sign	0	0	0
EC numbers	45,138	149	146
Any classification	6,972	42	36
Any underspecification	9,470	322	290
Miscellaneous	91,576,083	1,257	1,095
Words > 5	179,051	5,734	4,665

"Terms in corpus (all)" indicates the number of occurrences of the new terms generated by the rewrite rules and the terms suppressed by the suppression rules in the corpus. "Terms in corpus (distinct)" and "Concepts in corpus (distinct)" indicate the number of unique terms and concepts produced or suppressed by the rules that were found in the corpus. The row "Original" indicates the total number of terms found in corpus when no rewrite or suppression rule was applied.

ISSN: 2041-1480