Portal de Periódicos da CAPES

Low-level laser therapy for neck pain

2010; Elsevier BV; Volume: 375; Issue: 9716 Linguagem: Inglês

10.1016/s0140-6736(10)60296-6

1474-547X

Arianne P. Verhagen, Jasper M. Schellingerhout,

Myofascial pain diagnosis and treatment

Roberta Chow and colleagues (Dec 5, p 1897)1Chow RT Johnson MI Lopes-Martins RAB Bjordal JM Efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomised placebo or active-treatment controlled trials.Lancet. 2009; 347: 1897-1908Summary Full Text Full Text PDF Scopus (405) Google Scholar conclude that regular low-level laser therapy is effective in the management of neck pain. Theirs is a well designed systematic review, but our experience with such reviews in the specialty of musculoskeletal disorders makes us suspicious about the validity of the data used for the statistical pooling, and therefore the conclusions. We were able to retrieve most articles published in English. Assessment of these studies resulted in the following possible sources of bias: •Two studies2Ceccherelli F Altafini L Lo Castro G Avila A Ambrosio F Giron GP Diode laser in cervical myofascial pain: a double-blind study versus placebo.Clin J Pain. 1989; 5: 301-304Crossref PubMed Scopus (101) Google Scholar, 3Chow RT Heller GZ Barnsley L The effect of 300mW, 830nm laser on chronic neck pain: a double-blind, randomized, placebo-controlled study.Pain. 2006; 124: 201-210Summary Full Text Full Text PDF PubMed Scopus (143) Google Scholar had significant baseline differences in pain in favour of the active treatment group, which probably resulted in overestimation of the mean difference.•There is a typing error in Chow and colleagues' figure 4, which suggests a significant mean difference in the trial by Chow et al (2004).4Chow RT Barnsley L Heller GZ Siddall PJ A pilot study of low-power laser therapy in the management of chronic neck pain.J Musculoskelet Pain. 2004; 12: 71-81Crossref Scopus (18) Google Scholar However, the difference is non-significant in the original study. Since these studies provide three of the largest reported mean differences, we think that the overall mean difference is too optimistic. We also think that the reported heterogeneity was mainly due to clinical heterogeneity. Pooling of data from patients with non-specific neck pain, myofascial pain syndrome, and cervical osteoarthritis is in our view inappropriate. This notion is illustrated by the fact that the largest mean difference was found in the patients with cervical osteoarthritis (figure 4 in Chow and colleagues' paper). Therefore, although low-level laser therapy might be an effective treatment strategy, we think that Chow and colleagues' conclusion is based on an overestimation of the actual treatment effect and that their interpretation of the generalisability is unjust because of clinical heterogeneity. We declare that we have no conflicts of interest. Low-level laser therapy for neck pain – Authors' replyWe thank Arianne Verhagen and Jasper Schellingerhout for their comments and for bringing a typographical error in figure 4 to our attention. A correction of the data for the laser group in Chow et al (2004)1 from 27 to 21 mm reduces the combined mean difference by 0·45 mm. However, Verhagen and Schellingerhout's claim that pain improvement in this trial was not significant is inconsistent with the published trial report which stated that p=0·039. Moreover, data on significance in single trials are never used in meta-analytical calculations. Full-Text PDF