[1] RAND Corp, Pittsburgh, PA USA
[2] RAND Corp, Santa Monica, CA 90401 USA
[3] Kaiser Permanente Ctr Effectiveness & Safety Res, Pasadena, CA USA
[4] Ctr Medicare & Medicaid Serv, Off Minor Hlth, Baltimore, MD USA
[5] Ctr Medicare & Medicaid Serv, Baltimore, MD USA
[6] US Equal Employment Opportun Commiss, Washington, DC USA
[7] Carnegie Mellon Univ, Pittsburgh, PA 15213 USA