[1] Maastricht Univ, Med Ctr, Dept Surg, P Debyelaan 25, NL-6202 AZ Maastricht, Netherlands
[2] Maastricht Univ, Dept Family Practice, Care & Publ Hlth Res Inst, Univ Singel 40, NL-6229 ER Maastricht, Netherlands
[3] Maastricht Univ, Med Ctr, Dept Clin Epidemiol & Med Technol Assessment, Care & Publ Hlth Res Inst, P Debyelaan 25, NL-6202 AZ Maastricht, Netherlands
[4] Acad Hosp Maastricht, POB 5800, NL-6202 AZ Maastricht, Netherlands