HANOVER, N.H -- Patients with a herniated lumbar disk did about the same in reducing pain and disability over two years with surgery or usual care, according to two studies.
HANOVER, N.H., Nov. 21 -- For patients with a herniated lumbar disk, surgery and usual care appeared equally effective in reducing pain and disability over two years, according to two studies.
It was essentially a draw in the first randomized trial of lumbar diskectomy or to nonoperative individualized treatment for patients with lumbar disk intervertebral herniation, said investigators here.
Irrespective of the therapy, patients improved substantially and for the most part equally, James Weinstein, D.O., of Dartmouth Medical School here, and colleagues reported in the Nov. 22/29 issue of the Journal of the American Medical Association.
In a companion observational study of patients who declined to be randomized in the first trial but chose their own treatment, the results were similar, giving a slight edge to surgery, found a second report in the same issue of JAMA.
However, according to the researchers, a similar group in both studies, and two editorial writers, both studies had unavoidable methodological flaws, making it difficult to reach firm conclusions.
In the randomized controlled trial, The Spine Patient Outcomes Research Trial (SPORT), 501 surgical candidates were enrolled from 2000 to 2004 from 13 multidisciplinary spine clinics in 11 states. Patients (mean age, 42 years; 42% women) had imaging-confirmed lumbar intervertebral disk herniation and persistent signs and symptoms of radiculopathy for at least six weeks.
Of the patients, 232 were randomized to standard open diskectomy, while 240 were assigned to nonoperative treatment. The latter protocol included physical therapy (44%), education and counseling with home exercise instruction (93%), nonsteroidal anti-inflammatory drugs if tolerated (61%), opiates (46%), epidural steroid injections (more than 50%), and activity restriction (29%).
Intent-to-treat analysis measured regularly for up to two years from enrollment found substantial improvements for all primary and secondary outcomes in both treatment groups, the researchers reported.
Primary outcomes included changes from baseline for pain and physical function as measured by the Medical Outcomes Study Short-Form Health Survey and the modified Oswestry Disability Index (American Academy of Orthopaedic Surgeons MODEMS version).
Secondary outcomes included sciatic severity (Sciatica Bothersome Index), satisfaction with symptoms, self-reported improvement, and employment status.
Differences between the groups for reduction in pain and disability consistently favored surgery. Specifically, the results were small and not statistically significant in the primary measures, but not in the secondary measures of sciatica severity and self-rated improvement, the researchers reported.
There was little evidence of harm from either treatment, the researchers said. No patient in either group developed cauda equina syndrome, and 95% of the surgical patients had no intraoperative complications. The most common complication, dural tear, occurred in 4%, similar to results in other studies.
However, the study had a major methodological problem because adherence to the assigned treatment was limited, the researchers wrote. In the randomized trial, only 50% of the patients assigned to surgery received diskectomy within three months of enrollment, while 30% of those assigned to non-operative treatment also decided to have surgery in the same period.
Considering the differential risk of the two strategies, the researchers were not surprised, and they prepared for it by developing a parallel observational study of patients who qualified for the trial but refused randomization.
Those more likely to cross over to surgery, they said, tended to have lower incomes, worse baseline symptoms, more disability, and were more likely to rate their symptoms as getting worse, compared with the other usual-care patients.
Those more likely to switch from surgery to usual care were older, had higher incomes, were more likely to have had an upper-lumbar herniation, had less pain, better physical function, and were more likely to rate their symptoms as getting better compared with the other surgical patients.
Because of the large number of patients who crossed over in both directions, the researchers said, conclusions about the superiority or equivalence of the treatment are not warranted on the basis of the intent-to-treat analysis.
However, they noted the large effects seen in their as-treated analysis and the characteristics of the cross-over patients suggest that the intent-to-treat analysis underestimated the true effect of surgery.
Discussing the study's other limitations, the researchers noted that the choice of nonoperative treatments was at the discretion of the treating physician and the patient. However, given the limited evidence for most of these usual-care treatments, creating a fixed protocol of treatment was neither clinically feasible nor generalizable.
Still another limitation of SPORT was its potential lack of representativeness of the patients who agreed to be randomized.
Finally, Dr. Weinstein said that given the degree of crossover in both directions, it is unlikely that the analysis can form the basis of a valid estimate of the true effect of surgery.
For this reason, Dr. Weinstein and a partly overlapping group of researchers undertook the observational study of 743 SPORT patients who had declined randomization. Of these, 528 had surgery during the first two years, and 191 received nonoperative care.
At three months. patients who chose surgery had greater improvement in:
These differences narrowed somewhat between three months and two years but remained significant at all periods, the researchers said.
At two years patients who chose surgery had greater improvement in:
Study limitations included the fact that strict eligibility criteria may have limited the generalizability of the SPORT results (patients unable to tolerate symptoms for six weeks or those who preferred early surgical intervention were not included).
Also, the investigators said, to the degree that some nonoperative treatments were ineffective or inappropriate, the benefits of surgery may have been overestimated. However, the one-year improvement in the usual-care group was excellent.
An important limitation in the study design and in all such interventions is that when measuring subjective outcomes, differences in motivation and even in care may affect the results. In addition, people who elected to have surgery may have been different in unmeasured ways, including burden of disease, the researchers said.
In this nonrandomized evaluation, patients with persistent sciatica from lumbar disk herniation improved in both the operated and usual-care groups. However, those who chose surgery reported significantly greater improvements than patients who elected nonoperative care, the researchers reported.
However, they emphasized, nonrandomized comparisons of self-reported outcomes are subject to potential confounding and must be interpreted cautiously.
In an accompanying editorial, David Flum, M.D., of the University of Washington in Seattle, and a JAMA contributing editor, said that although the findings from the observational study suggest that surgery is more beneficial than usual care, this interpretation may be flawed.
Patients who elected to have surgery were different in many ways from those who declined. A higher level of disease severity among operative-care patients might be considered a conservative bias in that treatment effects among patients with similar disability might be even greater, he said.
But if anything has been learned from the legacy of sham-controlled trials, he said, these differences may also include a greater expectation of success among patients having the more invasive intervention.
How much of the observed difference in outcome in the SPORT trial is the result of these raised expectations can only be determined by studying the placebo effect through sham-controlled trials, Dr. Flum said.
Because of limitations in the design of the SPORT study, "the proper role and benefits of these competing interventions are still unclear. Given the large number of patients potentially exposed to the risks of these strategies, a sham surgical trial may be the only effective and ethical next step," Dr. Flum concluded.
In another editorial in the same issue, Eugene Carragee, M.D., of Stanford University wrote that these two studies "represent a colossal research effort and provide a fascinating snapshot of both modern patient preferences and clinical outcomes for this common clinical problem."
However, he said, in a study in which only half of those in the surgery group underwent the procedure three months after entry, these findings are difficult to evaluate.
Nonetheless, Dr. Carragee said, it is clear that both surgical and nonoperative treatment were associated with clinically significant improvement over time and that the differences between the two approaches, as has been shown in previous studies, decreased over time.
Among several important questions that remain, he said, is the need to establish the cost effectiveness of surgery and the role of pharmacologic treatments aimed at local inflammatory processes. Furthermore, technical advances allow less extensive procedures to decompress the nerve roots, and whether these approaches will lead to improvements or increase complications is unclear.
"The fear of many patients and surgeons that not removing a large disk herniation will likely have catastrophic neurologic consequences is simply not borne out," Dr. Carragee said. "Thus, these data help both clinicians and patients make better informed decision based on each patient's needs and expectations," he concluded.
Dr. Weinstein reported that he is the Editor-in-Chief of Spine, has been a consultant to UnitedHealth Care and has been a consultant to the Foundation for Informed Medical Decision Making, Dr Jon Lurie reported that he receives grant support from St Francis Medical Technologies and the American Board of Orthopaedic Surgery; has served on advisory boards for Ortho-MacNeil Pharmaceuticals, the Robert Graham Center of the American Academy of Family Practice, Pfizer and Centocor; and as a consultant for Myexpertdoctor.com, Pacific Business Group on Health, and the Foundation for Informed Medical Decision Making. Dr Anna Tosteson reported receiving funding from St Francis Medical Technologies. Brett Hanscom reported working for the National Spine Network and receiving funding from Medtronic. Dr. Scott Boden reported serving as a consultant for Medtronic. Dr. Richard Deyo reported receiving research program benefits as a gift to the University of Washington from Synthes, a manufacturer of surgical appliances, from which he receives no personal benefit.
Financial disclosures for authors of the observational study were similar to those cited for the randomized study. In addition Dr. Harry Herkowitz reported that he is the inventor of the Premier CervicalSpine Plate, serves as a consultant for Medtronics and is a board of director for Stryker Corp and Globus Medical. Dr. Frank Cammisa reported consulting for Spinal Kinetics,Healthpoint Capital, K2 Medical LLC, Mazor Surgical Technologies, Nuvasive, Orthovita Inc, Raymedica Inc, and Scient'x USA; he also has investments in Alphatec Holdings Inc, Healthpoint Capital Partners, Ivy Health Care, K2 Medical LLC, Nuvasive, Orthopedic Investment Partners Fund LP, Orthovita Inc, Paradigm Spine LLC, Pioneer Labs, Raymedica Inc, Small Bone Innovations Inc, and Spinal Kinetics; Dr Todd Albert reported that he served as a consultant for DePuy Spine, serves on the advisory board of and owns stock options in Axiamed-Medical, K2 Medical, and Gentis.