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Outcomes of lumbar discectomy
The Spine Journal 10 (2010) 167–168
Commentary
Outcomes of lumbar discectomy Jon D. Lurie, MD, MSa,b,* a Department of Medicine, Dartmouth Medical School, Hanover, NH, USA Department of Community and Family Medicine, Dartmouth Medical School, Hanover, NH, USA
b
Received 15 October 2009; accepted 7 November 2009
COMMENTARY ON: Sherman J, Cauthen J, Schoenberg D, et al. Economic impact of improving outcomes of lumbar discectomy. Spine J 2010;10:108–116 (in this issue).
Lumbar discectomy for relief of sciatica in patients with intervertebral disc herniation is one of the most wellresearched and common indications for spine surgery. Recent systematic and narrative reviews agree that there is good evidence that lumbar discectomy for carefully selected patients with sciatica because of lumbar disc herniation provides faster relief of symptoms than nonoperative treatment [1,2]. Yet despite these generally good outcomes, persistent symptoms and recurrent disc herniations occur more often than physicians and patients would like. In this issue of The Spine Journal, Sherman et al. [3] use administrative claims data to assess the results of lumbar discectomy. Using administrative claims for complications and additional testing/treatments in the 18 months after surgery, the authors find that 11% underwent reoperation, 13% had a procedure-related complication, and 28% of the subjects had some evidence of a ‘‘poor’’ outcome. They then go on to develop an economic model to calculate the potential impact of technologies that might improve these outcomes. These findings raise several important points when looked at in the context of data from several recent trials on lumbar discectomy. The first important point is that the rate of complications appears to be much higher in this study than in a number of recent studies of lumbar discectomy. Sherman et al. [3] show a 13% rate of procedurerelated complications and cite a literature-based estimate of 15%. In the recent trial by Peul et al. [4], the complication rate was found to be 1.6%; in the Spine Patient Outcomes DOI of original article: 10.1016/j.spinee.2009.08.453. FDA device/drug status: not applicable. Author disclosures: JDL (consulting, Foundation for Informed Medical Decision Making, Blue Cross Blue Shield; research support, Medtronic). * Corresponding author. SPORT/The Spine Center, Dartmouth Hitchcock Medical Center, Lebanon, NH 03756, USA. Tel.: (603) 650-8380; fax: (603) 653-9502. E-mail address: [email protected] (J.D. Lurie) 1529-9430/10/$ – see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.spinee.2009.11.013
Research Trial [5], it was 6%; and in the series by Carragee et al. [6], it was 10%. Similarly, Sherman et al. [3] found an 11% reoperation rate and cites a literature-based estimate of 15%; however, in the study by Peul et al. [4], the reoperation rate was only 6%; in the Spine Patient Outcomes Research Trial [5], it was 10%; in the series by Carragee et al. [6], it was 6%; in the trial by Butterman [7], it was 8%; in a series by Ambrossi et al. [8], it was 7%; and in a study by Pechlivanis et al. [9], it was 6.2%. There are several potential reasons for these discrepancies. One potential reason is the difficulty in using claims to identify complications because of the lack of specific clinical detail in the administrative data, although this should not affect the reoperation rate, which is well defined in administrative data. Another explanation is the selection of centers/ surgeons for participation in a clinical study. If only more experienced or accomplished surgeons participate in trials or publish their clinical series, then these results might be expected to be more favorable than a population-based estimate. Another explanation is the selection of patients for a clinical study. As pointed out by Frymoyer [10], ‘‘the choice of which procedure to perform in a patient with lumbar disc herniation appears to be less important than the careful selection of the patient.’’ Thus, careful selection criteria in the recent clinical studies may have contributed to better overall results than found in the claims-based analysis where patient selection was likely variable. This phenomenon was seen in the study by Keller et al. [11] who found that across three different geographic areas in Maine, the results in the areas with the highest rate of lumber decompressive surgery and thus the most lax selection criteria were substantially worse than the outcomes in the areas with lower rates of surgery and more stringent patient selection. The other major point of interest from the study by Sherman et al. relates to the levels of improvement assessed in their economic model. They calculate the acceptable cost
168
J.D. Lurie / The Spine Journal 10 (2010) 167–168
for an intervention, which would result in ‘‘moderate improvement’’ in postdiscectomy outcomes, which they define as a 50% reduction in poor outcomes. They do not evaluate any particular approaches or technologies against this standard but rather provide a ‘‘framework for the cost evaluation of these technologies.’’ It is worth thinking about this framework and putting the benchmarks it proposes into some perspective. First, as has already been shown, the outcomes in routine practice, such as the claims-based analysis looked at by Sherman, will often be worse than the results seen within the context of controlled clinical trials. As such, for a new technology to really reduce the rate of poor outcomes by 50% in routine clinical practice, and thus achieve the cost savings projected by the economic model, the results in controlled trials will have to be substantially better than 50% to account for the inevitable drop between efficacy in controlled studies and effectiveness in the ‘‘real world.’’ Perhaps more importantly, is a 50% reduction in poor outcomes a moderate improvement? In the context of most medical interventions, a 50% reduction tends to be a very large effect––interventions considered highly effective like thrombolytics for acute myocardial infarction reduce mortality by about 37% and aspirin after myocardial infarction reduces 2-year mortality by about 23% [12]. For disc herniation, the rate of patients who were not satisfied with their outcome at 2 years in the Spine Patient Outcomes Research Trial [5] was 49% in the nonoperative group and 25% in the surgery group, almost exactly a 50% reduction in poor outcome. Thus, the bar set by Sherman et al. for a ‘‘moderate’’ improvement in outcomes amounts to an intervention that is as effective in improving the outcomes of lumbar discectomy as lumbar discectomy itself is at improving the short-term outcomes of lumbar disc herniation relative to nonoperative treatment. A 50% reduction is thus a high bar that has been set, and Sherman determines that the cost of such a highly effective intervention would need to be less than $1,000 to maintain overall cost neutrality. One intervention has already been shown to almost meet these criteria. In the study by Keller et al. [11], careful patient selection in the area with a low rate of lumbar decompressive surgery was associated with 45% decrease in poor outcomes postoperatively, as measured by patient satisfaction with symptoms at follow-up, compared with more lax patient selection in the high-rate areas.
Highly effective and relatively low-cost approaches or technologies for improving the outcomes of lumbar discectomy would be a great boon for patients with lumbar disc herniation and their physicians. The challenge for a new technology to meet the criteria set by the economic model of Sherman et al. will be daunting, however, particularly if one considers the expected drop-off in effectiveness between the clinical trial results and the likely results in routine practice. In the meantime, efforts to improve and ensure the optimal selection of patients will likely remain the most effective and cost-effective approach for improving outcomes of lumbar discectomy.
References [1] Gibson JNA, Waddell G. Surgical interventions for lumbar disc prolapse. Cochrane Database Syst Rev 2007; Art. No.: CD001350. doi: 10.1002/14651858.CD001350.pub4. [2] Deyo RA. Back surgery—who needs it? N Engl J Med 2007;356: 2239–43. [3] Sherman J, Cauthen J, Schoenberg D, et al. Economic impact of improving outcomes of lumbar discectomy. Spine J 2010;10: 108–16. [4] Peul WC, van den Hout WB, Brand R, et al. Prolonged conservative care versus early surgery in patients with sciatica caused by lumbar disc herniation: two year results of a randomized controlled trial. BMJ 2008;336:1355–8. [5] Weinstein J, Tosteson T, Lurie J, et al. Surgical vs nonoperative treatment for lumbar disk herniation. The Spine Patient Outcomes Research Trial (SPORT): a randomized trial. JAMA 2006;296:2441–50. [6] Carragee EJ, Han MY, Suen PW, Kim D. Clinical outcomes after lumbar discectomy for sciatica: the effects of fragment type and annular competence. J Bone Joint Surg Am 2003;85-A:102–8. [7] Butterman GR. Treatment of lumbar disc herniation: epidural steroid injection compared with discectomy. A prospective, randomized study. J Bone Joint Surg Am 2004;86-A:670–9. [8] Ambrossi GL, McGirt MJ, Sciubba DM, et al. Recurrent lumbar disc herniation after single-level lumbar discectomy: incidence and health care cost analysis. Neurosurgery 2009;65:574–8. [9] Pechlivanis I, Kuebler M, Harders A, Schmieder K. Perioperative complication rate of lumbar disc microsurgery depending on the surgeon’s level of training. Cent Eur Neurosurg 2009;70:137–42. [10] Frymoyer JW. Back pain and sciatica. N Engl J Med 1988;318: 291–300. [11] Keller RB, Atlas SJ, Soule DN, et al. Relationship between rates and outcomes of operative treatment for lumbar disc herniation and spinal stenosis. J Bone Joint Surg Am 1999;81:752–62. [12] Sackett DL, Strauss SE, Richardson WS, et al. Evidence-based medicine: how to practice and teach EBM. 2nd ed. Edinburgh, UK: Churchill Livingstone, 2000:114.
Commentary
Outcomes of lumbar discectomy Jon D. Lurie, MD, MSa,b,* a Department of Medicine, Dartmouth Medical School, Hanover, NH, USA Department of Community and Family Medicine, Dartmouth Medical School, Hanover, NH, USA
b
Received 15 October 2009; accepted 7 November 2009
COMMENTARY ON: Sherman J, Cauthen J, Schoenberg D, et al. Economic impact of improving outcomes of lumbar discectomy. Spine J 2010;10:108–116 (in this issue).
Lumbar discectomy for relief of sciatica in patients with intervertebral disc herniation is one of the most wellresearched and common indications for spine surgery. Recent systematic and narrative reviews agree that there is good evidence that lumbar discectomy for carefully selected patients with sciatica because of lumbar disc herniation provides faster relief of symptoms than nonoperative treatment [1,2]. Yet despite these generally good outcomes, persistent symptoms and recurrent disc herniations occur more often than physicians and patients would like. In this issue of The Spine Journal, Sherman et al. [3] use administrative claims data to assess the results of lumbar discectomy. Using administrative claims for complications and additional testing/treatments in the 18 months after surgery, the authors find that 11% underwent reoperation, 13% had a procedure-related complication, and 28% of the subjects had some evidence of a ‘‘poor’’ outcome. They then go on to develop an economic model to calculate the potential impact of technologies that might improve these outcomes. These findings raise several important points when looked at in the context of data from several recent trials on lumbar discectomy. The first important point is that the rate of complications appears to be much higher in this study than in a number of recent studies of lumbar discectomy. Sherman et al. [3] show a 13% rate of procedurerelated complications and cite a literature-based estimate of 15%. In the recent trial by Peul et al. [4], the complication rate was found to be 1.6%; in the Spine Patient Outcomes DOI of original article: 10.1016/j.spinee.2009.08.453. FDA device/drug status: not applicable. Author disclosures: JDL (consulting, Foundation for Informed Medical Decision Making, Blue Cross Blue Shield; research support, Medtronic). * Corresponding author. SPORT/The Spine Center, Dartmouth Hitchcock Medical Center, Lebanon, NH 03756, USA. Tel.: (603) 650-8380; fax: (603) 653-9502. E-mail address: [email protected] (J.D. Lurie) 1529-9430/10/$ – see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.spinee.2009.11.013
Research Trial [5], it was 6%; and in the series by Carragee et al. [6], it was 10%. Similarly, Sherman et al. [3] found an 11% reoperation rate and cites a literature-based estimate of 15%; however, in the study by Peul et al. [4], the reoperation rate was only 6%; in the Spine Patient Outcomes Research Trial [5], it was 10%; in the series by Carragee et al. [6], it was 6%; in the trial by Butterman [7], it was 8%; in a series by Ambrossi et al. [8], it was 7%; and in a study by Pechlivanis et al. [9], it was 6.2%. There are several potential reasons for these discrepancies. One potential reason is the difficulty in using claims to identify complications because of the lack of specific clinical detail in the administrative data, although this should not affect the reoperation rate, which is well defined in administrative data. Another explanation is the selection of centers/ surgeons for participation in a clinical study. If only more experienced or accomplished surgeons participate in trials or publish their clinical series, then these results might be expected to be more favorable than a population-based estimate. Another explanation is the selection of patients for a clinical study. As pointed out by Frymoyer [10], ‘‘the choice of which procedure to perform in a patient with lumbar disc herniation appears to be less important than the careful selection of the patient.’’ Thus, careful selection criteria in the recent clinical studies may have contributed to better overall results than found in the claims-based analysis where patient selection was likely variable. This phenomenon was seen in the study by Keller et al. [11] who found that across three different geographic areas in Maine, the results in the areas with the highest rate of lumber decompressive surgery and thus the most lax selection criteria were substantially worse than the outcomes in the areas with lower rates of surgery and more stringent patient selection. The other major point of interest from the study by Sherman et al. relates to the levels of improvement assessed in their economic model. They calculate the acceptable cost
168
J.D. Lurie / The Spine Journal 10 (2010) 167–168
for an intervention, which would result in ‘‘moderate improvement’’ in postdiscectomy outcomes, which they define as a 50% reduction in poor outcomes. They do not evaluate any particular approaches or technologies against this standard but rather provide a ‘‘framework for the cost evaluation of these technologies.’’ It is worth thinking about this framework and putting the benchmarks it proposes into some perspective. First, as has already been shown, the outcomes in routine practice, such as the claims-based analysis looked at by Sherman, will often be worse than the results seen within the context of controlled clinical trials. As such, for a new technology to really reduce the rate of poor outcomes by 50% in routine clinical practice, and thus achieve the cost savings projected by the economic model, the results in controlled trials will have to be substantially better than 50% to account for the inevitable drop between efficacy in controlled studies and effectiveness in the ‘‘real world.’’ Perhaps more importantly, is a 50% reduction in poor outcomes a moderate improvement? In the context of most medical interventions, a 50% reduction tends to be a very large effect––interventions considered highly effective like thrombolytics for acute myocardial infarction reduce mortality by about 37% and aspirin after myocardial infarction reduces 2-year mortality by about 23% [12]. For disc herniation, the rate of patients who were not satisfied with their outcome at 2 years in the Spine Patient Outcomes Research Trial [5] was 49% in the nonoperative group and 25% in the surgery group, almost exactly a 50% reduction in poor outcome. Thus, the bar set by Sherman et al. for a ‘‘moderate’’ improvement in outcomes amounts to an intervention that is as effective in improving the outcomes of lumbar discectomy as lumbar discectomy itself is at improving the short-term outcomes of lumbar disc herniation relative to nonoperative treatment. A 50% reduction is thus a high bar that has been set, and Sherman determines that the cost of such a highly effective intervention would need to be less than $1,000 to maintain overall cost neutrality. One intervention has already been shown to almost meet these criteria. In the study by Keller et al. [11], careful patient selection in the area with a low rate of lumbar decompressive surgery was associated with 45% decrease in poor outcomes postoperatively, as measured by patient satisfaction with symptoms at follow-up, compared with more lax patient selection in the high-rate areas.
Highly effective and relatively low-cost approaches or technologies for improving the outcomes of lumbar discectomy would be a great boon for patients with lumbar disc herniation and their physicians. The challenge for a new technology to meet the criteria set by the economic model of Sherman et al. will be daunting, however, particularly if one considers the expected drop-off in effectiveness between the clinical trial results and the likely results in routine practice. In the meantime, efforts to improve and ensure the optimal selection of patients will likely remain the most effective and cost-effective approach for improving outcomes of lumbar discectomy.
References [1] Gibson JNA, Waddell G. Surgical interventions for lumbar disc prolapse. Cochrane Database Syst Rev 2007; Art. No.: CD001350. doi: 10.1002/14651858.CD001350.pub4. [2] Deyo RA. Back surgery—who needs it? N Engl J Med 2007;356: 2239–43. [3] Sherman J, Cauthen J, Schoenberg D, et al. Economic impact of improving outcomes of lumbar discectomy. Spine J 2010;10: 108–16. [4] Peul WC, van den Hout WB, Brand R, et al. Prolonged conservative care versus early surgery in patients with sciatica caused by lumbar disc herniation: two year results of a randomized controlled trial. BMJ 2008;336:1355–8. [5] Weinstein J, Tosteson T, Lurie J, et al. Surgical vs nonoperative treatment for lumbar disk herniation. The Spine Patient Outcomes Research Trial (SPORT): a randomized trial. JAMA 2006;296:2441–50. [6] Carragee EJ, Han MY, Suen PW, Kim D. Clinical outcomes after lumbar discectomy for sciatica: the effects of fragment type and annular competence. J Bone Joint Surg Am 2003;85-A:102–8. [7] Butterman GR. Treatment of lumbar disc herniation: epidural steroid injection compared with discectomy. A prospective, randomized study. J Bone Joint Surg Am 2004;86-A:670–9. [8] Ambrossi GL, McGirt MJ, Sciubba DM, et al. Recurrent lumbar disc herniation after single-level lumbar discectomy: incidence and health care cost analysis. Neurosurgery 2009;65:574–8. [9] Pechlivanis I, Kuebler M, Harders A, Schmieder K. Perioperative complication rate of lumbar disc microsurgery depending on the surgeon’s level of training. Cent Eur Neurosurg 2009;70:137–42. [10] Frymoyer JW. Back pain and sciatica. N Engl J Med 1988;318: 291–300. [11] Keller RB, Atlas SJ, Soule DN, et al. Relationship between rates and outcomes of operative treatment for lumbar disc herniation and spinal stenosis. J Bone Joint Surg Am 1999;81:752–62. [12] Sackett DL, Strauss SE, Richardson WS, et al. Evidence-based medicine: how to practice and teach EBM. 2nd ed. Edinburgh, UK: Churchill Livingstone, 2000:114.