Perception of confidentiality and adolescents' use of health care services and information: Jeannie S. Thrall, M.P.P., Lois McCloskey, Dr.P.H., Edward Rothstein, Ph.D., Susan L. Ettner, Ph.D., Howard Spivak, M.D., Joan E. Tighe, M.S.W., S. Jean Emans, M.D. Alliance for Young Families, Institute for Urban Health Policy and Research, Boston Department of Health and Hospitals, Center for Statistical Consultation and Research, University of Michigan, New England Medical Center, Harvard Medical School, and Children's Hospital, Boston Massachusetts