[1] Acad Ziekenhuis, Dept Clin Epidemiol & Med Technol Assessment, NL-6202 AZ Maastricht, Netherlands
[2] Acad Ziekenhuis, Dept Obstet & Gynaecol, NL-6202 AZ Maastricht, Netherlands
[3] Univ Maastricht, Dept Hlth Org Policy & Econ, NL-6200 MD Maastricht, Netherlands