[1] Univ N Carolina, Chapel Hill & Res Triangle Inst, Evidence Based Practice Ctr, Chapel Hill, NC 27514 USA
[2] Res Triangle Inst, Res Triangle Pk, NC 27709 USA
[3] Oregon Hlth & Sci Univ, Evidence Based Practice Ctr, Portland, OR USA
[4] Georgetown Univ, Ctr Med, Washington, DC USA