ORIGINAL ARTICLE Is low-level laser therapy in relieving neck pain effective? Systematic review and meta-analysis Amjed Kadhim-Saleh • Harinad Maganti • Michelle Ghert • Sheila Singh • Forough Farrokhyar Received: 24 January 2013 / Accepted: 22 March 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract The aim of this study is to determine the effi- cacy of low-level laser therapy (LLLT) in reducing acute and chronic neck pain as measured by the visual analog scale (VAS). A systematic search of nine electronic dat- abases was conducted to identify original articles. For study selection, two reviewers independently assessed titles, abstracts, and full text for eligibility. Methodological quality was assessed using the Detsky scale. Data were analyzed using random-effects model in the presence of heterogeneity and fixed-effect model in its absence. Het- erogeneity was assessed using Cochran’s Q statistic and quantifying I 2 . Risk ratios (RR) with 95 % confidence intervals (CI) were reported. Eight randomized controlled trials involving 443 patients met the strict inclusion criteria. Inter-rater reliability for study selection was 92.8 % (95 % CIs 80.9–100 %) and for methodological quality assess- ment was 83.9 % (95 % CIs 19.4–96.8 %). Five trials included patients with cervical myofascial pain syndrome (CMPS), and three trials included different patient popu- lations. A meta-analysis of five CMPS trials revealed a mean improvement of VAS score of 10.54 with LLLT (95 % CI 0.37–20.71; Heterogeneity I 2 = 65 %, P = 0.02). This systematic review provides inconclusive evidence because of significant between-study heterogeneity and potential risk of bias. The benefit seen in the use of LLLT, although statistically significant, does not constitute the threshold of minimally important clinical difference. Keywords Neck pain Á Laser therapy, low-level Á Myofascial pain syndrome Á Meta-analysis Abbreviations CI Confidence interval CID Clinical important difference CMPS Cervical myofascial pain syndrome ICC Intraclass correlation coefficient LLLT Low-level laser therapy RCT Randomized controlled trial RR Risk ratio VAS Visual analog scale Background Neck pain is one of the most common pain complaints encountered by primary care providers. There is great variation in the overall prevalence of neck pain between studies, ranging from 0.4 to 86.8 % in the general popu- lation, with a mean prevalence of 23.1 % [1]. Several mechanisms can lead to neck pain, including trauma, repetitive and forceful occupational movements, as well as pathological factors, such as inflammatory and neuro- logical conditions [2]. The consequences of neck pain range from minor discomfort to debilitating pain that interferes with daily living activities, work conditions, and sleep [3, 4]. A number of treatment options are available for patients with neck pain, including pharmacological, surgical, behavioral, and alternative therapies [3]. Low-level laser A. Kadhim-Saleh Á H. Maganti Faculty of Medicine, University of Ottawa, Ottawa, Canada M. Ghert Á S. Singh Á F. Farrokhyar (&) Department of Surgery, McMaster University, 39 Charlton Ave. E, Hamilton, ON L8N 1Y3, Canada e-mail: farrokh@mcmaster.ca F. Farrokhyar Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada 123 Rheumatol Int DOI 10.1007/s00296-013-2742-z