- Email: [email protected]
Reply to the Letter to the Editor
Letters to the Editor for low back pain (Cochrane Review). The Cochrane Library, Issue 2. Oxford: Update Software, 2000.
George Mendelson Caul®eld Pain Management and Research Centre, 260 Kooyong Road, Caul®eld, Victoria 3162, Australia PII: S 0304-395 9(01)00312-8 PAIN 4488
Reply to the Letter to the Editor Thank you for inviting us to respond to Dr Mendelson's letter regarding our systematic review of acupuncture for chronic pain. The number of inquiries we have received about this systematic review indicates it is clearly a topic of great interest. As systematic reviews are always works in progress, we appreciate inquiries about trials that were not included. Dr Mendelson mentions the trial by Garvey et al. (1989) and the one by Thomas and Lundeberg (1994). The trial by Garvey et al. was excluded because it did not meet our de®nition of chronic pain as 3 months or longer. Garvey et al. report only that patients with low back pain were treated conservatively for 4 weeks before entering the trial. Although it is not entirely clear from this description, this may suggest that the trial included a number of patients with pain of only 4 weeks' duration. When it was not clear from a published description of a trial whether it met all our inclusion criteria, we attempted to obtain that information from the author. When contact could be made, authors generously provided us with the information needed to con®rm inclusion (White et al., 1996; Dowson et al., 1985; Raustia et al., 1985) or exclusion (Shlay et al., 1998) with certainty. When contact could not be made, and it was not clear from the published description whether a trial met all of our inclusion criteria, such as the trial by Garvey et al., then the trial was excluded. The trial by Thomas and Lundeberg (1994) does meet all our inclusion criteria and should have been included. We appreciate this being brought to our attention, and subsequent versions of the review will include this. We have reanalyzed our results including this trial, and our results remain the same. This trial was a four-arm trial comparing three types of real acupuncture and a waiting list control. Our selection of control groups listed in the methods section include waiting list, placebo, sham acupuncture or standard medical care. Therefore, this would qualify in our review as an acupuncture vs waiting list control trial. Our conclusions based on the quality and number of the included trials was that there is limited evidence that
199
acupuncture is superior to waiting list. The Thomas and Lundeberg trial ®nds that acupuncture is superior to waiting list. It, therefore, supports our ®ndings, but does not change them. Acupuncture researchers who are very familiar with the acupuncture literature may have questions about whether a particular trial which does not appear in the review was intentionally or inadvertently omitted. To make our methods as transparent as possible, we have compiled a list of trials which were reviewed by us and excluded. We mention this list in our article and want to emphasize that this list that is available to anyone by writing or emailing us at the address below. There are approximately 70 excluded trials on that list, and in the interest of space, we documented these separately instead of citing all of them in the paper. This list serves as a valuable reference for readers comparing our review to other reviews because it also states the reason for exclusion. Several acupuncture researchers have inquired why some trials which were included in a prior systematic review on acupuncture and chronic pain (Ter Riet et al., 1990) were excluded by our review. The differences can be explained in different inclusion criteria. The previous review (Ter Riet et al., 1990) included both randomized and nonrandomized trials, whereas our review included only to the randomized controlled trial. The list details the differences on a trialby-trial basis for those interested in a particular trial. The second issue that Dr Mendelson raises is one of multiple publications of the same trial. There is a well-documented risk of bias in systematic reviews if a study population is counted more than once (Tramer et al., 1997) due to reviewers' failing to realize that multiple publications actually relate to the same trial. Therefore, multiple publications were carefully addressed by us. When we identi®ed more than one publication of the same trial, we assessed these to make sure that outcomes were consistent across publications. We cited one publication of that trial in the review and cross-referenced the other publications of that trial on the by-request list. We did this in the interest of space; however, we see from Dr Mendelson's letter that this caused some confusion. In future updates of the review, we will clarify this by citing all publications of an included trial in the manuscript and citing only excluded trials on the byrequest list. We would like to thank all those who have taken the time to correspond with us. In particular, we welcome information on trials we have not considered for review (i.e. trials not on the excluded trials list and not included in the review) whether they are planned, in progress, or published. We also welcome any additional information on the trials we excluded due to insuf®cient information that may result in their possible inclusion. Systematic reviews are works in progress that require being updated as more evidence accrues, and updates of this review will incorporate any newly gained information.
200
Letters to the Editor
References Dowson DI, Lewith GT, Machin D. The effects of acupuncture versus placebo in the treatment of headache. Pain 1985;21:35±42. Garvey TA, Marks MR, Wiesel SW. A prospective, randomized, doubleblind evaluation of trigger point injection therapy for low back pain. Spine 1989;14:962±964. Raustia AM, Pohjola RT, Virtanen KK. Acupuncture compared with stomatognathic treatment for TMJ dysfunction. Part I: a randomized study. J Prosthet Dent 1985;54:581±585. Shlay JC, Chaloner K, Max MB, Flaws B, Reichelderfer P, Wentworth D, Hillman S, Brizz B, Cohn DL. Acupuncture and amitryptiline for pain due to HIV-related peripheral neuropathy: a randomized, controlled trial. J Am Med Assoc 1998;280(18):1590±1595. Ter Riet G, Kleijnen J, Knipschild P. Acupuncture and chronic pain: a criteria-based meta-analysis. J Clin Epidemiol 1990;43(11):1191±1199. Thomas M, Lundeberg T. Importance of modes of acupuncture in the treatment of chronic nociceptive low back pain. Acta Anaestheiol Scand 1994;38:63±69.
Tramer MR, Reynolds DJM, Moore RA, McQuay J. Impact of covert duplicate publication on meta-analysis: a case study. Br Med J 1997;315:635±640. White AR, Eddleston C, Hardie R, Resch KL, Ernst E. A pilot study of acupuncture for tension headache using a novel placebo. Acupunct Med 1996;14:11±15. Jeanette Ezzo*, Brian Berman, Victoria Hadhazy, Alejandro Jadad, Lixing Lao, Betsy Singh 1905 West Rogers Avenue, Baltimore, MD 21209, USA * Tel.: 11-410-578-3467; fax: 11-410-578-1450. E-mail address: [email protected] (J. Ezzo).
PII: S0 304-3959(01 )00 313-X
George Mendelson Caul®eld Pain Management and Research Centre, 260 Kooyong Road, Caul®eld, Victoria 3162, Australia PII: S 0304-395 9(01)00312-8 PAIN 4488
Reply to the Letter to the Editor Thank you for inviting us to respond to Dr Mendelson's letter regarding our systematic review of acupuncture for chronic pain. The number of inquiries we have received about this systematic review indicates it is clearly a topic of great interest. As systematic reviews are always works in progress, we appreciate inquiries about trials that were not included. Dr Mendelson mentions the trial by Garvey et al. (1989) and the one by Thomas and Lundeberg (1994). The trial by Garvey et al. was excluded because it did not meet our de®nition of chronic pain as 3 months or longer. Garvey et al. report only that patients with low back pain were treated conservatively for 4 weeks before entering the trial. Although it is not entirely clear from this description, this may suggest that the trial included a number of patients with pain of only 4 weeks' duration. When it was not clear from a published description of a trial whether it met all our inclusion criteria, we attempted to obtain that information from the author. When contact could be made, authors generously provided us with the information needed to con®rm inclusion (White et al., 1996; Dowson et al., 1985; Raustia et al., 1985) or exclusion (Shlay et al., 1998) with certainty. When contact could not be made, and it was not clear from the published description whether a trial met all of our inclusion criteria, such as the trial by Garvey et al., then the trial was excluded. The trial by Thomas and Lundeberg (1994) does meet all our inclusion criteria and should have been included. We appreciate this being brought to our attention, and subsequent versions of the review will include this. We have reanalyzed our results including this trial, and our results remain the same. This trial was a four-arm trial comparing three types of real acupuncture and a waiting list control. Our selection of control groups listed in the methods section include waiting list, placebo, sham acupuncture or standard medical care. Therefore, this would qualify in our review as an acupuncture vs waiting list control trial. Our conclusions based on the quality and number of the included trials was that there is limited evidence that
199
acupuncture is superior to waiting list. The Thomas and Lundeberg trial ®nds that acupuncture is superior to waiting list. It, therefore, supports our ®ndings, but does not change them. Acupuncture researchers who are very familiar with the acupuncture literature may have questions about whether a particular trial which does not appear in the review was intentionally or inadvertently omitted. To make our methods as transparent as possible, we have compiled a list of trials which were reviewed by us and excluded. We mention this list in our article and want to emphasize that this list that is available to anyone by writing or emailing us at the address below. There are approximately 70 excluded trials on that list, and in the interest of space, we documented these separately instead of citing all of them in the paper. This list serves as a valuable reference for readers comparing our review to other reviews because it also states the reason for exclusion. Several acupuncture researchers have inquired why some trials which were included in a prior systematic review on acupuncture and chronic pain (Ter Riet et al., 1990) were excluded by our review. The differences can be explained in different inclusion criteria. The previous review (Ter Riet et al., 1990) included both randomized and nonrandomized trials, whereas our review included only to the randomized controlled trial. The list details the differences on a trialby-trial basis for those interested in a particular trial. The second issue that Dr Mendelson raises is one of multiple publications of the same trial. There is a well-documented risk of bias in systematic reviews if a study population is counted more than once (Tramer et al., 1997) due to reviewers' failing to realize that multiple publications actually relate to the same trial. Therefore, multiple publications were carefully addressed by us. When we identi®ed more than one publication of the same trial, we assessed these to make sure that outcomes were consistent across publications. We cited one publication of that trial in the review and cross-referenced the other publications of that trial on the by-request list. We did this in the interest of space; however, we see from Dr Mendelson's letter that this caused some confusion. In future updates of the review, we will clarify this by citing all publications of an included trial in the manuscript and citing only excluded trials on the byrequest list. We would like to thank all those who have taken the time to correspond with us. In particular, we welcome information on trials we have not considered for review (i.e. trials not on the excluded trials list and not included in the review) whether they are planned, in progress, or published. We also welcome any additional information on the trials we excluded due to insuf®cient information that may result in their possible inclusion. Systematic reviews are works in progress that require being updated as more evidence accrues, and updates of this review will incorporate any newly gained information.
200
Letters to the Editor
References Dowson DI, Lewith GT, Machin D. The effects of acupuncture versus placebo in the treatment of headache. Pain 1985;21:35±42. Garvey TA, Marks MR, Wiesel SW. A prospective, randomized, doubleblind evaluation of trigger point injection therapy for low back pain. Spine 1989;14:962±964. Raustia AM, Pohjola RT, Virtanen KK. Acupuncture compared with stomatognathic treatment for TMJ dysfunction. Part I: a randomized study. J Prosthet Dent 1985;54:581±585. Shlay JC, Chaloner K, Max MB, Flaws B, Reichelderfer P, Wentworth D, Hillman S, Brizz B, Cohn DL. Acupuncture and amitryptiline for pain due to HIV-related peripheral neuropathy: a randomized, controlled trial. J Am Med Assoc 1998;280(18):1590±1595. Ter Riet G, Kleijnen J, Knipschild P. Acupuncture and chronic pain: a criteria-based meta-analysis. J Clin Epidemiol 1990;43(11):1191±1199. Thomas M, Lundeberg T. Importance of modes of acupuncture in the treatment of chronic nociceptive low back pain. Acta Anaestheiol Scand 1994;38:63±69.
Tramer MR, Reynolds DJM, Moore RA, McQuay J. Impact of covert duplicate publication on meta-analysis: a case study. Br Med J 1997;315:635±640. White AR, Eddleston C, Hardie R, Resch KL, Ernst E. A pilot study of acupuncture for tension headache using a novel placebo. Acupunct Med 1996;14:11±15. Jeanette Ezzo*, Brian Berman, Victoria Hadhazy, Alejandro Jadad, Lixing Lao, Betsy Singh 1905 West Rogers Avenue, Baltimore, MD 21209, USA * Tel.: 11-410-578-3467; fax: 11-410-578-1450. E-mail address: [email protected] (J. Ezzo).
PII: S0 304-3959(01 )00 313-X