1. Department of Chronic Illness, Johns Hopkins University School of Nursing, Baltimore, MD, USA
2. Department of Natural Sciences/Nursing, University of Houston-Downtown, Houston, TX, USA
3. Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
4. Department of Statistics, The George Washington University, Washington, DC, USA
5. School of Nursing, University of Arkansas, Fayetteville, AR, USA
6. Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA