Study Design. Randomized trial with a concurrent observational cohort study.
Objective. To compare 8-year outcomes of surgery with nonoperative care for symptomatic lumbar spinal stenosis.
Summary of Background Data. 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.
Conclusion. 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.
Level of Evidence: 1
Eight-year outcomes for the SPORT lumbar spinal stenosis (SpS) surgical and nonoperative cohorts are reported. Overall, 428 patients with SpS underwent surgery at some point during the first 8 years; 226 remained nonoperative. The as-treated analyses in the randomized cohort showed convergence in outcomes over time with no significant advantage to surgery at 6 to 8 years, whereas in the observational cohort, the significant advantages for surgery previously reported were maintained through 8 years.
*Geisel School of Medicine, Hanover, NH
†The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, NH; and
‡Dartmouth-Hitchcock Medical Center, Lebanon, NH.
Address correspondence and reprint requests to Jon D. Lurie, MD, MS, Section of Hospital Medicine, Dartmouth-Hitchcock Medical Center, One Medical Center Dr, Lebanon, NH 03756; E-mail: firstname.lastname@example.org
Acknowledgment date: September 8, 2014. First revision date: November 30, 2014. Acceptance date: December 2, 2014.
The manuscript submitted does not contain information about medical device(s)/drug(s).
The National Institute of Arthritis and Musculoskeletal and Skin Diseases (U01-AR45444, P60-AR048094 and P60-AR062799) and the Office of Research on Women's Health, the National Institutes of Health, and the National Institute of Occupational Safety and Health, the Centers for Disease Control and Prevention, funds were received in support of this work.
Relevant financial activities outside the submitted work: consultancy, stocks, travel/accommodations/meeting expenses.