istoph Roder, Achim Elfering, Jean-Claude Theis, Urs Muller, Lukas P. Staub, Emin Aghayev, Thomas Zweig, Thomas Ban, Thomas Kuhlmann, Simon Wieser, Peter Juni, and Marcel Zwahlen, "Differences Across Health Care Systems in Outcome and Cost-Utility of Surgical and Conservative Treatment of Chronic Low Bac