1. Department of Epidemiology and Biostatistics, Temple University College of Public Health, Philadelphia, PA (E.R.K.).
2. Department of Medicine, University of Washington, Seattle (J.D.K., C.S.).
3. Department of Environmental and Occupational Health Sciences, University of Washington, Seattle (J.D.K., C.S.).
4. Department of Epidemiology, University of Washington, Seattle (J.D.K.).