Specific Aim #1: Sample Power V2.0 (SPSS) was used for sample size calculation based on the convention outlined by Cohen6. Overall experiment wise error was held to ?=0.05, and power to 80% using medium (0.25) effect sizes. Correction for multiplicity of tests (2 tests for primary hypotheses) involved using ?=0.025 (0.05/2). This yielded 125 patients per group. In addition, the sample was inflated to account for an estimated 20% attrition at 1 year of follow-up (death, relocation, or loss to follow-up). No more than 150 eligible patients need to be enrolled per group. Thus, 300 patients (150 Whites and 150 African Americans) will be recruited.