[1] Univ Minnesota, Sch Nursing, Minneapolis, MN 55455 USA
[2] Univ Minnesota, Dept Family Med & Community Hlth, Minneapolis, MN 55455 USA
[3] Univ Minnesota, Div Epidemiol & Community Hlth, Minneapolis, MN 55455 USA
[4] Duke Univ, Community & Family Med & Global Hlth, Durham, NC USA