title: Open discectomy vs microdiscectomy for lumbar disc herniation - a protocol for a pragmatic comparative effectiveness study.
abstract: Introduction:  Since the introduction of lumbar microdiscectomy in the 1970's, many studies have attempted to compare the effectiveness of this method with that of standard open discectomy with conflicting results. This observational study is designed to compare the relative effectiveness of microdiscectomy (MD) with open discectomy (OD) for treating lumbar disc herniation, -within a large cohort, recruited from daily clinical practice.Methods and analysis:This study will include patients registered in the Norwegian Registry for Spine Surgery (NORspine). This clinical registry collects prospective data, including preoperative and postoperative outcome measures as well as individual and demographic parameters. The primary outcome is change in Oswestry disability index between baseline and 12 months after surgery. Secondary outcome measures are improvement of leg pain and changes in health related quality of life measured by the Euro-Qol-5D between baseline and 12 months after surgery, complications to surgery, duration of surgical procedures and length of hospital stay.
authors.affiliation: The Norwegian National Registry for Spine Surgery (NORspine), University Hospital of North Norway (UNN), Tromsø, Norway; Department of Neurosurgery, University Hospital of North Norway (UNN), Tromsø, Norway.
authors.forename: Andreas
authors.initials: A
authors.lastname: Sørlie
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, Norway; National Advisory Unit on Spinal Surgery, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: Sasha
authors.initials: S
authors.lastname: Gulati
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, Norway; National Advisory Unit on Spinal Surgery, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: Charalampis
authors.initials: C
authors.lastname: Giannadakis
authors.affiliation: Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Endocrinology, St. Olavs University Hospital, Trondheim, Norway.
authors.forename: Sven M
authors.initials: SM
authors.lastname: Carlsen
authors.affiliation: Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: Øyvind
authors.initials: Ø
authors.lastname: Salvesen
authors.affiliation: Department of Neurosurgery, St. Olavs University Hospital, Trondheim, Norway; National Advisory Unit on Spinal Surgery, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: Øystein P
authors.initials: ØP
authors.lastname: Nygaard
authors.affiliation: The Norwegian National Registry for Spine Surgery (NORspine), University Hospital of North Norway (UNN), Tromsø, Norway; Department of Neurosurgery, University Hospital of North Norway (UNN), Tromsø, Norway; Department of Clinical Medicine, University of Tromsø, Tromsø, Norway.
authors.forename: Tore K
authors.initials: TK
authors.lastname: Solberg
keywords: Discectomy; Effectiveness; Microdiscectomy; Propensity match; Registry; comparative; multicenter; pragmatic (study protocol)