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Archived Comments for: Study Protocol- Lumbar Epidural Steroid Injections for Spinal Stenosis (LESS): a double-blind randomized controlled trial of epidural steroid injections for lumbar spinal stenosis among older adults

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  1. Study Protocol ¿ Lumbar Epidural Steroid Injections for Spinal STENOSIS (LESS): A Double-Blind Randomized Controlled Trial of Epidural Steroid Injections for Lumbar Spinal Stenosis Among Older Adults

    Laxmaiah Manchikanti, Pain Management Center of Paducah

    19 July 2012

    We read with great interest the study protocol by Friedly et al for lumbar epidural injections for spinal stenosis [1]. The protocol is well designed and a useful contribution to the literature. Unfortunately, the authors have demonstrated a seemingly superficial approach with what is potentially a misinterpretation of the previously available research. With reference to the previous available research, the authors have quoted a preliminary article by Manchikanti et al [2] published in 2008; however, they have ignored multiple other publications in reference to the one-year follow-up of the complete manuscript of the 2008 publication [3] as well as lumbar interlaminar epidural injections for spinal stenosis by the same authors and other multiple manuscripts by various other authors. The deficiencies of Manchikanti et al¿s manuscript, as described by Friedly et al, are inappropriate. They stated that, ¿this study suffered significant methodological limitations including lack of statistical power, no primary outcome measure, un-blinding of patients and researchers and a high dropout rate (21/60 patients) (SIC).¿ In reference to statistical power, the authors may be accurate in that this was a preliminary report with only 40 patients included in the study; however, the limitations have been noted clearly by the authors. However, the one-year follow-up published in the Journal of Spinal Disorders and Techniques [3] included 100 patients, with 50 patients in each group, which provides an adequate sample size as also described in the 2008 publication. The authors also have mistakenly stated that there was no primary outcome measure. Significant pain relief and also significant improvement in disability score were defined clearly. The authors also claim that there was unblinding of patients and researchers; however, there was no unblinding and this has been explained clearly in the blinding (masking) section that all the patients for one-year follow-up were selected by a statistician not participating in the provision of patient care. The unblinding results were not disclosed to either the treating physician or other participants or patients. Thus, the nature of blinding was not interrupted.
    Finally, the authors claim that there was a high dropout rate of 21 of 60 patients. As the authors of that study, we wish to clarify that this was not a dropout rate. There were 61 patients enrolled in the study by that time, as it is illustrated in Figure 1 of the manuscript and 40 of them completed the one-year follow-up. In the recent manuscript, which was published in 2011, 100 patients were randomized and they all participated, with 50 patients in each group. Further, the withdrawal rate at 12 months for 50 patients in Group I was 18%; it was 20% in Group II. Even in the prior publication in 2008, the intent-to-treat analysis was performed on 7 occasions at 12 months for missing data in Group I and 5 occasions for missing data at 12 months in Group II. We hope that this clarifies the issue of dropout rate. There was only one patient in Group I and 2 patients in Group II who were dropouts in the preliminary report.
    We appreciate Friedly¿s protocol and look forward to seeing the results of the study. However, it is extremely important in evidence-based medicine and comparative effectiveness research that the facts be provided.

    Laxmaiah Manchikanti, MD
    Clinical Professor of Anesthesiology and Perioperative Medicine
    University of Louisville, Kentucky
    Medical Director, Pain Management Center of Paducah
    Paducah, KY

    Joshua A Hirsch, MD
    Chief of Minimally Invasive Spine Surgery, Depts. of Radiology and Neurosurgery, Massachusetts General Hospital
    Associate Professor of Radiology
    Harvard Medical School
    Boston, MA

    Frank J.E. Falco, MD
    Medical Director of Mid Atlantic Spine and Pain Physicians, Newark DE
    Director, Pain Medicine Fellowship and Associate Professor, Department of PM and R
    Temple University Medical School
    Philadelphia, PA

    1. Friedly JL, Bresnahan BW, Comstock B, Turner JA, Deyo RA, Sullivan SD, Heagerty P, Bauer Z, Nedeljkovic SS, Avins AL, Nerenz D, Jarvik JG: Study Protocol- Lumbar Epidural Steroid Injections for Spinal Stenosis (LESS): a double-blind randomized controlled trial of epidural steroid injections for lumbar spinal stenosis among older adults. BMC Musculoskelet Disord 2012, 29(13):48.
    2. Manchikanti L, Cash KA, McManus CD, Pampati V, Abdi S: Preliminary results of randomized, equivalence trial of fluoroscopic caudal epidural injections in managing chronic low back pain: Part 4. Spinal stenosis. Pain Physician 2008, 11(6):833-848.
    3. Manchikanti L, Cash RA, McManus CD, Pampati V, Fellows B: Fluoroscopic caudal epidural injections with or without steroids in managing pain of lumbar spinal stenosis: One year results of randomized, double-blind, active-controlled trial. J Spinal Disord 2011, April 5 [Epub ahead of print].

    Competing interests

    None declared