1. Department of Gerontology, University of Nebraska Omaha, 312 Nebraska Hall, 901 North 17 Street, Lincoln, NE 68588-0562, USA
2. Department of Gerontology, University of Nebraska Omaha, Omaha, NE, USA
3. Creighton University College of Nursing, Omaha, NE, USA
4. University of Nebraska Medical Center College of Nursing, Omaha, NE, USA
5. University of Nebraska Medical Center College of Public Health, Omaha, NE, USA