Table 1.

Characteristics of the study cohort (United States Veterans Affairs): white and African American male veterans with at least one hospital admission between October 1, 1980, and September 30, 1996, who were followed more than one year

	Whites		African Americans
Characteristics	Other than MGUS	MGUS	Other than MGUS	MGUS
No. subjects	3 248 795	1 312	749 020	734
Mean age at study entry, y*	53.8	63.7	49.4	61.5
Time of follow-up, y, mean†	10.0	4.2	10.0	4.4
Person y at risk†	32 347 635	5 557	7 519 478	3 226
Mean age at ascertainment of MGUS, y	NA	68.3	NA	66.2
Mean age at diagnosis of multiple myeloma, y	68.2	69.5	66.5	67.5
No. multiple myeloma cases	2217	105	1150	74
Median no. hospital visits	3	9	3	8

NA indicates not applicable.

^*Age at first discharge record for inpatient hospitalization at Veterans Affairs hospitals between October 1, 1980, and September 30, 1996

^†The first year of follow-up was censored