[1] Martin Luther Univ Halle Wittenberg, Inst Hlth & Nursing Sci, Med Fac, Halle, Germany
[2] Uniklin RWTH Aachen, Aachen, Germany
[3] Witten Herdecke Univ, Fac Hlth, Sch Nursing Sci, Witten, Germany
[4] Heinrich Heine Univ Dusseldorf, Inst Gen Practice ifam, Ctr Hlth & Soc chs, Med Fac, Dusseldorf, Germany
[5] Martin Luther Univ Halle Wittenberg, Inst Hlth & Nursing Sci, Med Fac, Magdeburger Str 8, D-06112 Halle, Saale, Germany