[1] VAMC, Providence, RI 02908 USA
[2] Brown Univ, Providence, RI 02912 USA
[3] VA Cooperat Studies Program, Perry Point, MD USA
[4] Univ Maryland, College Pk, MD 20742 USA
[5] Univ Penn, Sect Gen Med, Philadelphia, PA 19104 USA
[6] Philadelphia VAMC, Philadelphia, PA USA
[7] W Los Angeles VAMC, Los Angeles, CA USA
[8] Univ Calif Los Angeles, Los Angeles, CA 90024 USA
[9] Denver VAMC, Denver, CO USA
[10] Univ Colorado, Sch Med, Boulder, CO 80309 USA
[11] Pittsburgh VAMC, Pittsburgh, PA USA
[12] Case Western Reserve Univ, Cleveland, OH 44106 USA