Table 4.

Number of features in each category (diagnosis, medication, and laboratory) for Hospital A, Hospital B, and those shared between them.

Features		Training Set (Hospital A), n	External Set (Hospital B), n	Shared, n
Baseline
	Total	9559	7926	5275
	ICDa diagnosis codes	7708	6859	4392
	Medi-Span drug names	1311	531	531
	LOINCb codes	540	536	352
Grouped
	Total	805	817	805
	CCSc diagnosis codes	287	287	287
	Medi-Span drug groups	94	94	94
	LOINC groups	424	436	424

^aICD: International Classification of Diseases.

^bLOINC: Logical Observation Identifiers Names and Codes.

^cCCS: Clinical Classification Software.