| Affiliation: | 1. Idiap Research Institute, Martigny, Switzerland;2. École Polytechnique Fédérale de Lausanne (EPFL), Switzerland;1. Institute for Evaluative Research in Medicine, Stauffacherstrasse 78, 3014 Bern, Switzerland;2. Spine Centre Division, Department of Teaching, Research and Development, Schulthess Klinik, Lengghalde 2, CH-8008 Zurich, Switzerland;3. Comparative Effectiveness, Cost and Outcome Research Centre, University of Washington, 4333 Brooklyn Ave NE, Seattle, WA 98104, USA;4. Department of Orthopaedic Surgery, Salem Spital, Schänzlistrasse 39, Bern 3025, Switzerland |
