[Acupuncture for musculoskeletal pain: A meta-analysis and meta-regression of sham-controlled randomized clinical trials] 2016

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4965798/

Abstract

The aims of this systematic review were to study the analgesic effect of real acupuncture and to explore whether sham acupuncture (SA) type is related to the estimated effect of real acupuncture for musculoskeletal pain. Five databases were searched. The outcome was pain or disability immediately (≤1 week) following an intervention. Standardized mean differences (SMDs) with 95% confidence intervals were calculated. Meta-regression was used to explore possible sources of heterogeneity. Sixty-three studies (6382 individuals) were included. Eight condition types were included. The pooled effect size was moderate for pain relief (59 trials, 4980 individuals, SMD −0.61, 95% CI −0.76 to −0.47; P < 0.001) and large for disability improvement (31 trials, 4876 individuals, −0.77, −1.05 to −0.49; P < 0.001). In a univariate meta-regression model, sham needle location and/or depth could explain most or all heterogeneities for some conditions (e.g., shoulder pain, low back pain, osteoarthritis, myofascial pain, and fibromyalgia); however, the interactions between subgroups via these covariates were not significant (P < 0.05). Our review provided low-quality evidence that real acupuncture has a moderate effect (approximate 12-point reduction on the 100-mm visual analogue scale) on musculoskeletal pain. SA type did not appear to be related to the estimated effect of real acupuncture.

Musculoskeletal disorders and the related pain are major causes of disability in both developed and developing countries1. Neck pain (NP), low back pain (LBP), osteoarthritis (OA), rheumatoid arthritis (RA), lateral epicondylitis, fibromyalgia (FM), and myofascial pain (MP) are common in our society2,3,4. Although mortality from these conditions is generally low, they have a major effect on disability, medical costs and patient quality of life, largely due to the associated musculoskeletal pain5. As the population continues to increase in age, the influence of musculoskeletal disorders on society will also increase. Currently, there is limited understanding of the mechanisms that cause musculoskeletal pain, and few therapies are available to treat musculoskeletal pain.

Acupuncture is commonly used for pain relief. The treatment is based on the theory that illness results from imbalances in energy flow, or qi, and fine needles are inserted at specific points on the body to correct these imbalances and restore harmony6. The incidences of side effects and adverse events with acupuncture are lower than that with opioid analgesics and anti-inflammatory medications7. Acupuncture has been claimed to be effective for a wide range of conditions, such as pain, musculoskeletal disorders and several neurologic diseases8. Gate control theory and the release of endogenous opioids have been suggested as explanations for the apparent analgesic effect of acupuncture9,10,11. Acupuncture has both physiologic and psychological effects12,13that are described as either specific or non-specific. The specific effects refer to the analgesic effects produced by needling a specific site at a proper depth for an appropriate duration and number of treatment sessions. The psychological non-specific effects are associated with patient perceptions, beliefs, experiences, and expectations of patients. Therefore, sham acupuncture (SA) is needed to assess the specific effects of acupuncture. “Sham” or “placebo” is used to describe any control procedure that is used to blind treatment allocation in clinical trials of acupuncture14. Several sham procedures are now available, such as the use of penetrating acupuncture on non-acupoints, superficial penetration of the skin on acupoints and nonpenetration on acupoints with sham needle devices14.

Several reviews15,16,17 have evaluated the effects of acupuncture for musculoskeletal pain. However, all of them focused on only one disorder and almost all of them lacked analysis of the impact of SA type on the assessment of real acupuncture for musculoskeletal pain. Thus, we sought to analyze all previous studies of acupuncture for musculoskeletal pain that included a SA control group. Our objectives were to study the analgesic effect of real acupuncture and to explore whether SA type is related to the estimated effect of real acupuncture.