title: The use of surgery for cervical degenerative disease in Norway in the period 2008-2014 : A population-based study of 6511 procedures.
abstract: BACKGROUND
  The incidence rate of surgical treatment of cervical degenerative diseases (CDD) has increased in the USA and a large geographic variation has been shown. Little is known about such rates in Scandinavia and Europe. The aim of this population-based study was to (1) investigate annual incidence rates of operations performed in Norway, (2) to compare trends and variations in rates for surgical indications with and without myelopathy, and (3) to compare variations in the use of surgery between residential areas.
  
  
  METHODS
  Patients operated for CDD and recorded in the Norwegian Patient Registry from 2008 to 2014 were evaluated according to residential areas (resident county and Regional Health Authority (RHA) area), age, gender, treating hospital, and whether myelopathy was present or not. Surgical rates were adjusted for age and gender. Data from private health care were also included.
  
  
  RESULTS
  The annual surgical rates increased by 74.1 % from 2008 to 2014 (12.5/100,000 inhabitants). The largest increase was for surgical treatment of radiculopathy, 86.5 %. Surgical rates for CDD varied in 2014 with a ratio of 1.5 between the highest and lowest RHA and with a ratio of 2.5 between the different residential counties within one RHA. The treatment rates for myelopathy were relatively stable over time, but showed an increase of 2.1/100,000 (44.6 %) from 2013 to 2014.
  
  
  CONCLUSIONS
  Our study shows that the rate of surgical treatment for radiculopathy due to CDD has increased substantially from 2008 to 2014 for all RHAs in Norway. The incidence rate for surgical treatment of myelopathy was more stable. An unexplained and moderate geographic variation was found.
authors.affiliation: Diakonhjemmet Hospital, Diakonveien 12, 0370, Oslo, Norway. jon.a.kristiansen@gmail.com.
authors.forename: Jon-André
authors.initials: JA
authors.lastname: Kristiansen
authors.affiliation: Center of Clinical Documentation and Evaluation, Northern Norway Regional Health Authority, Postbox 6, 9038, Tromsø, Norway.
authors.forename: Lise
authors.initials: L
authors.lastname: Balteskard
authors.affiliation: Department of Neurosurgery, Oslo University Hospital, Sognsvannsveien 20, 0424, Oslo, Norway.
authors.forename: Haldor
authors.initials: H
authors.lastname: Slettebø
authors.affiliation: Department of Neurosurgery, St. Olavs Hospital, Trondheim University Hospital, Sluppen, NO-7006, Postbox 3250, Trondheim, Norway.
authors.forename: Øystein P
authors.initials: ØP
authors.lastname: Nygaard
authors.affiliation: Department of Neurosurgery, Oslo University Hospital, Kirkeveien 166, 0450, Oslo, Norway.
authors.forename: Bjarne
authors.initials: B
authors.lastname: Lied
authors.affiliation: Department of Neurosurgery, Oslo University Hospital, Sognsvannsveien 20, 0424, Oslo, Norway.
authors.forename: Frode
authors.initials: F
authors.lastname: Kolstad
authors.affiliation: Department of Neurosurgery, University Hospital of North Norway, Tromsø, Norway.
authors.forename: Tore K
authors.initials: TK
authors.lastname: Solberg
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000601:surgery*; D005260:Female; D006801:Humans; D015994:Incidence; D055959:Intervertebral Disc Degeneration / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000706:statistics & numerical data*; D009664:Norway / Q000453:epidemiology; D011843:Radiculopathy / Q000601:surgery; D012042:Registries; D012189:Retrospective Studies; D012737:Sex Factors; D013118:Spinal Cord Diseases / Q000150:complications / Q000453:epidemiology; D013123:Spinal Fusion / Q000379:methods
keywords: Cervical degenerative disease; Geographic variation; Myelopathy; Radiculopathy; Surgery rates