Table I.

Comparison of Selected Features

Criterion	MedDRA (ratings in grey borrowed from Bousquet et al.) [22]	SNOMED CT	CTCAE, v.3
Selected Terminology Desiderata[19]
Vocabulary content – comprehensive for AE domain; should include signs, symptoms, lab values, diseases and disorders.	E	E	F
Concept orientation	E	E	F
Concept orientation	E	E	E
Concept permanence	E	E	E
Non-semantic concept identifiers	E	E	E
Polyhierarchy	P	E	N/A
Formal definitions	N	E	N
Rejection of ‘not elsewhere classified terms’	N	N	N
Multiple granularities	F	E	N/A
Multiple consistent views	P	E	N
Context representation	P	F	P
Graceful evolution	E	E	E
Recognized redundancy	N	F/P	N
Coding system type	terminology	terminology	classification
Post-coordination	no	yes	N/A
Incorporated in UMLS	yes	yes	yes
Designed specifically for representing AEs	yes	no	yes
Scope	AEs, PE findings, Medical History	Clinical findings	Toxicities
Global acceptance for AE reporting (i.e., ICH)	yes	no	no
FDA acceptance	yes	Yes for SPL; no for AE	no
Mappings to other possible standards	yes	yes	some
Free or low-cost use – US Users	no	yes	yes
Free or low-cost use – International Users	no	some	yes
Already in-use for Pharmaceutical Companies	yes	no	some
“Human readable” concept definitions	no	no	yes
Established rules for assigning codes	yes	some	yes
Training & Guidance Resources exist	E	P	E
Training & Guidance Resources are affordable/accessible	fee	fee	free
Previous/Demonstrated Organizational Experience in Adverse Events	yes	no	yes
Explicit Severity Grading	no	no	yes

E=Excellent, F=Fair, P=Poor, N=None; N/A = Not applicable