[1] Univ Hosp Cologne, Inst Hlth Econ & Clin Epidemiol, Cologne, Nordrhein Westf, Germany
[2] Univ Cologne, Fac Human Sci, Inst Med Sociol, Hlth Serv Res & Rehabil Sci IMVR, Cologne, Nordrhein Westf, Germany
[3] Univ Cologne, Fac Med, Cologne, Nordrhein Westf, Germany
[4] Univ Cologne, Dept Business Adm & Hlth Care Management, Cologne, Nordrhein Westf, Germany
[5] Carl von Ossietzky Univ Oldenburg, Fac Med & Hlth Sci, Dept Hlth Serv Res, Div Org Hlth Serv Res, Oldenburg, Lower Saxony, Germany