Surgery Favored in Latest SPORT Data
BY LAUREN UZDIENSKI, MAY 30, 2007
Spinal fusion is evaluated in the second of three SPORT studies, and patients who selected the surgery to treat degenerative spondylolisthesis had better outcomes when compared with nonsurgical treatment. However, when the results were analyzed on an intention-to-treat basis, there was no statistically significant difference in outcomes between the surgical and nonsurgical groups.
The study consisted of both a randomized and observational cohort. In the randomized cohort, 304 patients were randomly selected to receive either standard posterior decompressive laminectomy with or without fusion or nonsurgical care. Nonsurgical care included physical therapy, epidural steroid injections, NSAIDS, and opioids. The 303 patients in the observational cohort chose whether to have surgery or receive nonsurgical treatment.
Despite randomization and patient selection, there was significant crossover in patient treatment. Of patients in the randomized cohort, 64% of the surgical group had surgery, compared with 49% of patients assigned to nonsurgical care. In the observational group, 97% of patients who selected surgery went through with the operation, and 25% of the nonsurgical group ultimately chose surgical treatment.
Outcomes were evaluated based on combined data from both cohorts. In the intention-to-treat analysis, where outcomes were considered based on which treatments patients were assigned at the beginning of the study, no significant advantage for surgery was identified. The study's authors note that the results were "severely limited" by crossover.
On an as-treated basis, surgery was superior to nonsurgical treatment. The paper, published in this week's New England Journal of Medicine, states, "[Benefits of surgery were] seen as early as at the 6-week follow-up and persisted over two years." These benefits included less pain, increased physical function and lower Oswestry scores than seen with nonsurgical treatment.
The authors describe nonadherance to randomized treatment as one of the study's limitations; another is the lack of explicit protocol for nonsurgical treatments, even though such a protocol would be inappropriate given the absence of evidence showing nonsurgical treatments' efficacy. With nonrandomized results inclined toward surgery, the new data echoes the results of the first SPORT study: participants fared best when their care was left to the individual discretion of patient and surgeon.
