[1] Univ Freiburg, Med Ctr, Cochrane Germany, Berliner Allee 29, D-79110 Freiburg, Germany
[2] Univ Freiburg, Med Ctr, Dept Neurol, Breisacher Str 64, D-79106 Freiburg, Germany
[3] UroEvidence Deutsch Gesell Urol, Berlin, Germany
[4] Univ Freiburg, Med Ctr, Inst Med Biometry & Stat, Stefan Meier Str 26, D-79104 Freiburg, Germany
[5] Klinikum Bremen Mitte, Prof Hess Kinderklin, Sankt Jurgen Str 1, D-28177 Bremen, Germany
[6] Hop Hotel Dieu, Ctr Rech Epidemiol & Stat, INSERM, Sorbonne Paris,Cochrane France, 1 Pl Parvis Notre Dame, F-75181 Paris 04, France