Table 3.

Impact of data aggregation on drugs and conditions

	PHARMetrics		GE
	Native	Transformed	Native	Transformed
Total persons	32818355		10278445
Drug aggregation
Total Drug Eras	718590080	309797580	231492741	96614637
Eras per person	21.90	9.44	22.52	9.4
Average exposure length	31 days	79 days	NA	108 days
Rofecoxib
Total persons	349929	186763
Total rofecoxib Eras	1423273	510078	652234	264654
Eras per person	4.07	1.46	3.49	1.42
Average exposure length	34 days	99 days	NA	102 days
Condition aggregation
Total Condition Eras	3627194305	804977267	81693914	61795940
Eras per person	110.52	24.53	7.95	6.01
Average Condition Era length	NA	6 days	NA	88 days
Acute myocardial infarction (AMI)
Total persons	221437	53063
Total AMI Eras	5547711	292980	85940	53290
AMI Eras per person	25.05	1.32	1.62	1.00
Average Condition Era length	NA	11 days	NA	175 days