1. Center for Outcomes Research and Evaluation, Maine Medical Center Research Institute, Portland, Maine, USA.
2. Tufts University School of Medicine, Boston, Massachusetts, USA.
3. Division of Palliative Medicine, Maine Medical Center, Portland, Maine, USA.
4. University of Maine, Orono, Maine, USA.
5. Department of Family Medicine, Larner College of Medicine, and University of Vermont, Burlington, Vermont, USA.
6. College of Engineering and Mathematical Sciences, University of Vermont, Burlington, Vermont, USA.
7. Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, Maryland, USA.