[1] Carl von Ossietzky Univ Oldenburg, Fac Med & Hlth Sci, Dept Hlth Serv Res, D-26111 Oldenburg, Germany
[2] Univ Cologne, Fac Human Sci, Inst Med Sociol Hlth Serv Res & Rehabil Sci IMVR, Cologne, Germany
[3] Univ Cologne, Fac Med, Cologne, Germany
[4] Univ Hosp Cologne, Dept Urol, Cologne, Germany
[5] Univ Hosp Bonn, Ctr Hlth Commun & Hlth Serv Res, Dept Psychosomat Med & Psychotherapy, Bonn, Germany
[6] Hlth Res Men GmbH, Berlin, Germany