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

Original Text

Dr Roberta T Chow MBBS a Corresponding AuthorEmail Address, Prof Mark I Johnson PhD b, Prof Rodrigo AB Lopes-Martins PhD c, Prof Jan M Bjordal PT d e
Summary
Background
Neck pain is a common and costly condition for which pharmacological management has limited evidence of efficacy and side-effects. Low-level laser therapy (LLLT) is a relatively uncommon, non-invasive treatment for neck pain, in which non-thermal laser irradiation is applied to sites of pain. We did a systematic review and meta-analysis of randomised controlled trials to assess the efficacy of LLLT in neck pain.

Methods
We searched computerised databases comparing efficacy of LLLT using any wavelength with placebo or with active control in acute or chronic neck pain. Effect size for the primary outcome, pain intensity, was defined as a pooled estimate of mean difference in change in mm on 100 mm visual analogue scale.

Findings
We identified 16 randomised controlled trials including a total of 820 patients. In acute neck pain, results of two trials showed a relative risk (RR) of 1·69 (95% CI 1·22—2·33) for pain improvement of LLLT versus placebo. Five trials of chronic neck pain reporting categorical data showed an RR for pain improvement of 4·05 (2·74—5·98) of LLLT. Patients in 11 trials reporting changes in visual analogue scale had pain intensity reduced by 19·86 mm (10·04—29·68). Seven trials provided follow-up data for 1—22 weeks after completion of treatment, with short-term pain relief persisting in the medium term with a reduction of 22·07 mm (17·42—26·72). Side-effects from LLLT were mild and not different from those of placebo.

Interpretation
We show that LLLT reduces pain immediately after treatment in acute neck pain and up to 22 weeks after completion of treatment in patients with chronic neck pain.

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a Nerve Research Foundation, Brain and Mind Research Institute, University of Sydney, Sydney, NSW, Australia
b Faculty of Health, Leeds Metropolitan University, Leeds, UK
c Institute of Biomedical Sciences, Pharmacology Department, University of São Paulo, São Paulo, Brazil
d Faculty of Health and Social Science, Institute of Physiotherapy, Bergen University College, Bergen, Norway
e Section of Physiotherapy Science, Institute of Public Health and Primary Health Care, University of Bergen, Bergen, Norway
Corresponding Author Information Correspondence to: Dr Roberta T Chow, Honorary Research Associate, Nerve Research Foundation, Brain and Mind Research Institute, University of Sydney, 100 Mallett Street, Sydney, NSW 2050, Australia

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2809%2961522-1/fulltext