title: Long-term outcomes of lumbar spinal stenosis: eight-year results of the Spine Patient Outcomes Research Trial (SPORT).
abstract: METHODS
  Randomized trial with a concurrent observational cohort study.
  
  
  OBJECTIVE
  To compare 8-year outcomes of surgery with nonoperative care for symptomatic lumbar spinal stenosis.
  
  
  BACKGROUND
  Surgery for spinal stenosis has been shown to be more effective than nonoperative treatment during 4 years, but longer-term data are less clear.
  
  
  METHODS
  Surgical candidates from 13 centers in 11 US states with at least 12 weeks of symptoms and confirmatory imaging were enrolled in a randomized cohort or observational cohort. Treatment was standard, decompressive laminectomy versus standard nonoperative care. Primary outcomes were SF-36 (MOS 36-Item Short-Form Health Survey) Bodily Pain and Physical Function scales and the modified Oswestry Disability Index assessed at 6 weeks, 3 months, 6 months, and yearly up to 8 years.
  
  
  RESULTS
  Data were obtained for 55% of participants in the randomized group and 52% of participants in the observational group at the 8-year follow-up. Intent-to-treat analyses showed no differences between randomized cohorts; however, 70% of those randomized to surgery and 52% of those randomized to nonoperative had undergone surgery by 8 years. As-treated analyses in the randomized group showed that the early benefit for surgery out to 4 years converged over time, with no significant treatment effect of surgery seen in years 6 to 8 for any of the primary outcomes. In contrast, the observational group showed a stable advantage for surgery in all outcomes between years 5 and 8. Patients who were lost to follow-up were older, less well-educated, sicker, and had worse outcomes during the first 2 years in both surgical and nonoperative arms.
  
  
  CONCLUSIONS
  Patients with symptomatic spinal stenosis show diminishing benefits of surgery in as-treated analyses of the randomized group between 4 and 8 years, whereas outcomes in the observational group remained stable. Loss to follow-up of patients with worse early outcomes in both treatment groups could lead to overestimates of long-term outcomes but likely not bias treatment effect estimates.
authors.affiliation: *Geisel School of Medicine, Hanover, NH †The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, NH; and ‡Dartmouth-Hitchcock Medical Center, Lebanon, NH.
authors.forename: Jon D
authors.initials: JD
authors.lastname: Lurie
authors.forename: Tor D
authors.initials: TD
authors.lastname: Tosteson
authors.forename: Anna
authors.initials: A
authors.lastname: Tosteson
authors.forename: William A
authors.initials: WA
authors.lastname: Abdu
authors.forename: Wenyan
authors.initials: W
authors.lastname: Zhao
authors.forename: Tamara S
authors.initials: TS
authors.lastname: Morgan
authors.forename: James N
authors.initials: JN
authors.lastname: Weinstein
mesh_terms: D000368:Aged; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007796:Laminectomy; D059012:Lost to Follow-Up; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D013130:Spinal Stenosis / Q000601:surgery*; D016896:Treatment Outcome