Table 2.

Descriptive statistics of relations between drugs and their associated attributes in the National NLP Clinical Challenges (n2c2) data set.

Relation type	Relations, n (%)	Drugs with 1 link, n (%)	Drugs with more than 1 link, n (%)
Strength-drug	10,946 (18.88)	10,639 (97.20)	307 (2.8)
Frequency-drug	10,344 (17.84)	10,054(97.20)	290 (2.8)
Route-drug	9084 (15.67)	8903 (98.01)	181 (1.99)
Reason-drug	8579 (14.80)	7704 (89.80)	875 (10.2)
Dosage-drug	6920 (11.94)	6765 (97.76)	155 (2.2)
Form-drug	11,028 (19.02)	6511 (59.04)	4517 (40.96)
Duration-drug	1069 (1.84)	1021 (95.51)	48 (5)