Institution: | 1. Department of Statistics, North Carolina State University, Raleigh, North Carolina 27695‐8203, U.S.A.;2. Department of Biostatistics and Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599‐7420, U.S.A.;3. Texas Department of State Health Services, Austin, Texas 78714‐9347, U.S.A. |