Jump to comment:

• Reply to dr. Arts et al. on Reply on “Cost-effectiveness of full endoscopic versus open discectomy for sciatica” P. Gadjari et al., Br J Sports Med 2022”
  Biswadjiet Harhangi
  Published on: 5 September 2022
• Reply on “Cost-effectiveness of full endoscopic versus open discectomy for sciatica” P. Gadjari et al., Br J Sports Med 2022
  Mark Arts, Wouter Moojen and Ronald Bartels
  Published on: 5 September 2022

• Published on: 5 September 2022

  Reply to dr. Arts et al. on Reply on “Cost-effectiveness of full endoscopic versus open discectomy for sciatica” P. Gadjari et al., Br J Sports Med 2022”

  • Biswadjiet Harhangi, Neurosurgeon Erasmus MC, Rotterdam, The Netherlands

  Dear editor,
  On behalf of the PTED study group, we would like to thank the authors for the rapid response on our recently published paper “Cost-effectiveness of Full Endoscopic versus Open Discectomy for Sciatica [1]. The authors mention that they don’t agree with the conclusion of this study and have several comments. Below we will respond to these comments.

  Firstly, the authors suggest that “another study design is needed to investigate cost-effectiveness of PTED above conventional microdiscectomy.” We strongly disagree. The study design was an economic evaluation alongside a pragmatic randomized controlled trial examining the cost-effectiveness of full-endoscopic versus open discectomy for sciatica. An economic evaluation alongside a pragmatic randomised controlled trial is considered an adequate design, because it provides timely information on an intervention’s cost-effectiveness with high internal and sufficient external validity [2]. Furthermore, the study design was peer reviewed by the grant agency (ZONMW in the Netherlands) and we have pre-published our study protocol in an open access, peer reviewed journal [3], supported in a covenant agreement including the Dutch Neurosurgical Society (NVvN), Dutch Orthopedical Society (NOV), Dutch Spine Society and the Dutch Association for patients with low back pain (NVVR).

  Secondly, the authors comment that “costs associated with endoscope equipment and disposables were not included in their cost measur...

  Show More

  Dear editor,
  On behalf of the PTED study group, we would like to thank the authors for the rapid response on our recently published paper “Cost-effectiveness of Full Endoscopic versus Open Discectomy for Sciatica [1]. The authors mention that they don’t agree with the conclusion of this study and have several comments. Below we will respond to these comments.

  Firstly, the authors suggest that “another study design is needed to investigate cost-effectiveness of PTED above conventional microdiscectomy.” We strongly disagree. The study design was an economic evaluation alongside a pragmatic randomized controlled trial examining the cost-effectiveness of full-endoscopic versus open discectomy for sciatica. An economic evaluation alongside a pragmatic randomised controlled trial is considered an adequate design, because it provides timely information on an intervention’s cost-effectiveness with high internal and sufficient external validity [2]. Furthermore, the study design was peer reviewed by the grant agency (ZONMW in the Netherlands) and we have pre-published our study protocol in an open access, peer reviewed journal [3], supported in a covenant agreement including the Dutch Neurosurgical Society (NVvN), Dutch Orthopedical Society (NOV), Dutch Spine Society and the Dutch Association for patients with low back pain (NVVR).

  Secondly, the authors comment that “costs associated with endoscope equipment and disposables were not included in their cost measurements. The direct costs only included time of the operating room, costs of medications and overnight hospital stay.” This is not entirely correct. In the article we wrote “Costs of the interventions include the time of the operating room used, the costs of the medications used during the surgery and for open microdiscectomy also the cost for one overnight hospital stay.” We didn’t state ‘only’. The PTED and OM prices were based on the corresponding so-called Diagnosis- Treatment Combinations (DBC) prices that are being used in the Netherlands. The cost associated with endoscope equipment and disposables are included, as DBCs include all costs related to the procedure (i.e. the whole package). [Note: In the Dutch health care system, treatment costs and related hospital reimbursement encompass a fixed price for each patient, defined as DBC. However, these reimbursements can differ between hospitals depending on the agreement with the health insurer.] As the PTED price was not set in stone yet, because it was not yet included in the Netherlands public health system, we also conducted sensitivity analyses in which two scenarios of PTED intervention costs were considered. In the high-cost scenario, the cost of PTED was €5000/patient, that is, €500 more than in the main analysis. In the low-cost scenario, the cost of PTED and open microdiscectomy were equal, that is, €4095 per patient. In both sensitivity analyses, the result is that PTED is dominant compared with OM. This shows that the findings are robust and hence not influenced by surgical costs but more based on productivity-related costs.

  Thirdly, the authors state that for adequate comparison of costs, it should have been better when both groups had the same postoperative strategy, either both treatments in daycare, or both treatments with overnight stay. This study was funded by ZONMW’s program Healthcare Efficiency in which new interventions are typically compared with usual care. When we started this study, the most commonly used surgical technique in the Netherlands for this population was open microdiscectomy with mostly one night at the hospital. This was acknowledged by peer review. During the last couple of years more clinics/surgeons have started offering open microdiscectomy and consequently a relevant question for future research might be whether PTED is cost-effective compared with ‘daycare’ open microdiscectomy. However, the cost of one day of hospitalization in the Netherlands is approximately euro 500. We conducted a sensitivity analysis in which the cost of PTED was increased with euro 500, which is similar to one day of hospitalization. So, even if both PTED and open microdiscectomy would be associated with one day of hospitalization, the results and conclusion would be the same.

  Fourthly, the authors state that the study “ultimately did not reach the initial sample size of 682 patients.” This is right and we have discussed this in the effectiveness paper in BMJ [4]. The pre-estimated sample size of 682 patients was not reached. Of the 382 patients calculated to be necessary in the final sample size of the trial (i.e., excluding learning curve cases), we were able to include 179 instead of 191 of the patients who would undergo PTED. We argue that it is unlikely that the results would have been different with 682 instead of the 613 patients that were finally included. It may have resulted in a more precise effect estimate (slightly smaller confidence interval), but not in a clinically relevant change in the effect estimate itself. The sensitivity analysis including the learning curve (N= 613) confirms the robustness of our findings.

  Fifthly, the authors state that “long-term outcome data is needed to determine whether treatment with PTED will have the same revision rate as standard microdiscectomy.” We agree that long-term data are needed and therefore we have extended the follow-up of our trial to 5 years. We will analyze and publish these data once they are available.

  In summary, we don’t agree with the authors of the letter who stated that they don’t agree with the conclusion of this study. The methods are state-of-the art, the results are robust, and the conclusion of this large study reflects the results. The results of our study suggest that PTED can be considered as a cost-effective alternative to open microdiscectomy in treating sciatica.

  References

  1 Gadjradj PS, Broulikova HM, van Dongen JM, et al. Cost-effectiveness of full endoscopic versus open discectomy for sciatica. Br J Sports Med 2022;:bjsports-2021-104808. doi:10.1136/BJSPORTS-2021-104808
  2 Ramsey SD, Willke RJ, Glick H, et al. Cost-Effectiveness Analysis Alongside Clinical Trials II—An ISPOR Good Research Practices Task Force Report. Value Heal 2015;18:161–72. doi:10.1016/J.JVAL.2015.02.001
  3 Seiger A, Gadjradj PS, Harhangi BS, et al. PTED study: Design of a non-inferiority, randomised controlled trial to compare the effectiveness and cost-effectiveness of percutaneous transforaminal endoscopic discectomy (PTED) versus open microdiscectomy for patients with a symptomatic lumbar disc he. BMJ Open Published Online First: 2017. doi:10.1136/bmjopen-2017-018230
  4 Gadjradj PS, Rubinstein SM, Peul WC, et al. Full endoscopic versus open discectomy for sciatica: randomised controlled non-inferiority trial. BMJ 2022;376:e065846. doi:10.1136/bmj-2021-065846

  Show Less

  Conflict of Interest:
  None declared.

  • Back to top
• Published on: 5 September 2022

  Reply on “Cost-effectiveness of full endoscopic versus open discectomy for sciatica” P. Gadjari et al., Br J Sports Med 2022

  • Mark Arts, Neurosurgeon Haaglanden Medical Center
  • Other Contributors:
    • Wouter Moojen, Neurosurgeon
    • Ronald Bartels, Neurosurgeon

  We like to commend the authors with the recent publication of the results of a multicenter randomized controlled trial comparing percutaneous transforaminal discectomy (PTED) versus open microdiscectomy in the treatment of patients with symptomatic lumbar disc herniation[1].
  Based on the data of the non-inferiority trial, we fully agree with the authors conclusion that PTED is non-inferior to open microdiscectomy and can therefore be considered as an effective alternative surgical treatment. The improvement of leg pain and low back in the first 3 months is similar between both groups within the non-inferior margin. Patients treated with PTED seem to report less leg pain (mean difference 7.1) and low back pain (mean difference 6.0) at 12 months. However, these differences were small and did not reach the minimal clinically important difference of 20 mm on a VAS score[2].
  In contrast to the BMJ paper, we do not agree with the suggestion stated in the Br J Sports Med paper, that PTED is less costly and more effective for various reasons. Firstly, costs associated with endoscope equipment and disposables were not included in their cost measurements. The direct costs only included time of the operating room, costs of medications and overnight hospital stay. Secondly, the study protocol reported that all PTED procedures should be performed in daycare and the open microdiscectomy patients were admitted in the hospital for one to two days[3]. For adequate comparison of...

  Show More

  We like to commend the authors with the recent publication of the results of a multicenter randomized controlled trial comparing percutaneous transforaminal discectomy (PTED) versus open microdiscectomy in the treatment of patients with symptomatic lumbar disc herniation[1].
  Based on the data of the non-inferiority trial, we fully agree with the authors conclusion that PTED is non-inferior to open microdiscectomy and can therefore be considered as an effective alternative surgical treatment. The improvement of leg pain and low back in the first 3 months is similar between both groups within the non-inferior margin. Patients treated with PTED seem to report less leg pain (mean difference 7.1) and low back pain (mean difference 6.0) at 12 months. However, these differences were small and did not reach the minimal clinically important difference of 20 mm on a VAS score[2].
  In contrast to the BMJ paper, we do not agree with the suggestion stated in the Br J Sports Med paper, that PTED is less costly and more effective for various reasons. Firstly, costs associated with endoscope equipment and disposables were not included in their cost measurements. The direct costs only included time of the operating room, costs of medications and overnight hospital stay. Secondly, the study protocol reported that all PTED procedures should be performed in daycare and the open microdiscectomy patients were admitted in the hospital for one to two days[3]. For adequate comparison of costs, it should have been better when both groups had the same postoperative strategy, either both treatments in daycare, or both treatments with overnight stay. Microdiscectomy in daycare is currently already standard in many hospitals. Thirdly, although the authors are rewarded for excluding the initial 50 patients treated with PTED during the learning curve, they ultimately did not reach the initial sample size of 682 patients.
  Therefore, we disagree with the conclusion of the authors. Although PTED is non-inferior to conventional microdiscectomy, any conclusion about cost effectiveness cannot be made. In our opinion, another study design is needed to investigate the cost effectiveness of PTED above conventional microdiscectomy. Furthermore, long-term outcome data is needed to determine whether treatment with PTED will have the same revision rate as standard microdiscectomy. Only evaluation stage 3 according to the IDEAL framework for surgical innovation is now partly fulfilled[4]. Microdiscectomy will thus remain the golden standard for treating of patients with symptomatic lumbar disc herniation.

  References
  1. Gadjradj PS, Rubinstein SM, Peul WC et al. Full endoscopic versus open discectomy for sciatica: randomised controlled non-inferiority trial. BMJ 2022; 376: e065846.
  2. Ostelo RW, de Vet HC. Clinically important outcomes in low back pain. Best Pract Res Clin Rheumatol 2005; 19: 593-607.
  3. Seiger A, Gadjradj PS, Harhangi BS et al. PTED study: design of a non-inferiority, randomised controlled trial to compare the effectiveness and cost-effectiveness of percutaneous transforaminal endoscopic discectomy (PTED) versus open microdiscectomy for patients with a symptomatic lumbar disc herniation. BMJ Open 2017; 7: e018230.
  4. IDEAL framework for surgical innovation 3: randomised controlled trials in the assessment stage and evaluations in the long term study stage. Jonathan A Cook, Peter McCulloch, Jane M Blazeby, David J Beard, Danica Marinac-Dabic, Art Sedrakyan BMJ. 2013; 346: f2820. Published online 2013 Jun 18. doi: 10.1136/bmj.f2820

  Show Less

  Conflict of Interest:
  None declared.

  • Back to top