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SPINE Volume 37, Number 2, pp 140–149 ©2012, Lippincott Williams & Wilkins

SURGERY

Who Should Have Surgery for an Intervertebral Disc Herniation?
Comparative Effectiveness Evidence From the Spine Patient Outcomes Research Trial
Adam Pearson, MD, MS, Jon Lurie, MD, MS, Tor Tosteson, ScD, Wenyan Zhao, MS, William Abdu, MD, MS, Sohail Mirza, MD, MPH, and James Weinstein, DO, MS

Study Design.Combined prospective randomized controlled trial and observational cohort study of intervertebral disc herniation (IDH), an as-treated analysis. Objective. To determine modifiers of the treatment effect (TE) of surgery (the difference between surgical and nonoperative outcomes) for intervertebral disc herniation (IDH) using subgroup analysis. Summary of Background Data. The Spine Patient OutcomesResearch Trial demonstrated a positive surgical TE for IDH at the group level. However, individual characteristics may affect TE. No prior studies have evaluated TE modifiers in IDH. Methods. IDH patients underwent either discectomy (n = 788) or nonoperative care (n = 404) and were analyzed according to treatment received. Thirty-seven baseline variables were used to define subgroups for calculating thetime-weighted average TE for the Oswestry Disability Index (ODI) across 4 years (TE = ΔODIsurgery ΔODInonoperative). Variables with significant subgroup-bytreatment interactions (P < 0.1) were simultaneously entered into a multivariate model to select independent TE predictors. Results. All analyzed subgroups improved significantly more with surgery than with nonoperative treatment (P < 0.05). Inminimally adjusted univariate analyses, being married, absence of joint problems, worsening symptom trend at baseline, high school education or less, older age, no worker’s compensation, longer duration of symptoms, and an SF-36 mental component score (MCS) less than 35 were associated with greater TEs. Multivariate analysis demonstrated that being married (TE, −15.8 vs. −7.7 single, P < 0.001),absence of joint problems (TE, −14.6 vs. −10.3 joint problems, P = 0.012), and worsening symptoms (TE, −15.9 vs. −11.8 stable symptoms, P = 0.032) were independent TE modifiers.
Dartmouth Medical School, Department of Orthopaedics, One Medical Center Dr. Lebanon, NH. Acknowledgment date: July 29, 2010. Revision date: January 11, 2011. Acceptance date: January 18, 2011. The manuscript submitted doesnot contain information about medical device(s)/drug(s). Federal funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript. Address correspondence and reprint requests to Adam Pearson, MD, MS, Dartmouth Medical School, Department of Orthopaedics, One Medical Center Dr.Lebanon, NH 03756; E-mail: adam.m.pearson@hitchcock.org DOI: 10.1097/BRS.0b013e3182276b2b

TEs were greatest in married patients with worsening symptoms (−18.3) vs. single patients with stable symptoms (−7.8). Conclusion. IDH patients who met strict inclusion criteria improved more with surgery than with nonoperative treatment, regardless of specific characteristics. However, being married, withoutjoint problems, and worsening symptom trend at baseline were associated with a greater TE. Key words: lumbar disc herniation, comparative effectiveness research, treatment effect prediction, shared decision making. Spine 2012;37:140–149

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he Spine Patient Outcomes Research Trial (SPORT) demonstrated a clear benefit of surgery compared with nonoperative treatment for lumbar intervertebral discherniation (IDH) across 4 years.1–3 However, these findings were at the group level, and it has been shown that demographic, radiographic, clinical, and psychological characteristics can affect individual outcomes.4–13 The Institute of Medicine and Congress have defined comparative effectiveness research as a top priority with a goal of “assisting consumers, clinicians, purchasers, and policy makers to...