Approach to Assess Adequacy of Acupuncture in Randomized Controlled Trials: A Systematic Review

Disease-Related Factors Associated with Acupuncture Response in Patients with Chronic Tension-Type Headache: A Secondary Analysis of A Randomized Controlled Trial

OBJECTIVE

To explore the demographic and disease-related factors associated with acupuncture response in patients with chronic tension-type headache (CTTH).

METHODS

Using data from a randomized clinical trial (218 cases) consisting of 4 weeks of baseline assessment, 8 weeks of treatment, and 24 weeks of follow-up, participants were regrouped into responders (at least a 50% reduction in monthly headache days at week 16 compared with baseline) and non-responders. Twenty-three demographic and disease-related factors associated with acupuncture response in 183 participants were analyzed by multivariable logistic regression.

RESULTS

One hundred and nineteen (65.0%) participants were classified as responders. Four factors were significantly independently associated with acupuncture response, including treatment assignment, headache intensity at baseline, and 2 domains [general health (GH) and social functioning (SF)] from the 36-Item Short Form Health Survey quality of life questionnaire. Treatment assignment was associated with non-response: participants receiving true acupuncture were 3-time more likely to achieve a CTTH response than those receiving superficial acupuncture [odds ratio (OR) 0.322, 95% confidence interval (CI) 0.162 to 0.625, P=0.001]. Compared with patients with mild-intensity headache, patients with moderate-intensity headache were twice as likely to respond to acupuncture (OR 2.001, 95% CI 1.020 to 4.011, P=0.046). The likelihood of non-response increased by 4.5% with each unit increase in the GH grade (OR 0.955, 95% CI 0.917 to 0.993, P=0.024) while decreased by 3.8% with each unit increase in the SF grade (OR 1.038, 95% CI 1.009 to 1.069, P=0.011).

CONCLUSIONS

Greater headache intensity, lower GH score, and higher SF score were associated with better acupuncture responses in CTTH patients. These 3 factors require independent validation as predictors of acupuncture effectiveness in CTTH.

Factors and Their Impact on Treatment Effect of Acupuncture in Different Outcomes: A Meta-Regression of Acupuncture Randomized Controlled Trials

BACKGROUND

The effects of acupuncture have varied in different randomized controlled trials (RCTs), and there are many factors that influence treatment effect of acupuncture in different outcomes, with conflicting results.

OBJECTIVE

To identify factors and their impact on the treatment effect of acupuncture in different outcomes.

METHODS

Acupuncture RCTs were searched from 7 databases including Medline (PubMed), Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Wanfang Database, VIP Database, and China Biology Medicine disc between January 1st, 2015 and December 31st, 2019. Eligible studies must compare acupuncture to no acupuncture, sham acupuncture, or waiting lists, and report at least 1 patient-important outcome. A multi-level meta-regression was conducted using a 3-level robust mixed model and univariate analyses were performed for all independent variables, even those excluded from the multivariable model due to collinearities. We used thresholds of 0.2 and 0.4 for the difference of standardized mean differences (SMDs), categorising them as small (<0.2), moderate (0.2-0.4), or large (>0.4) effects.

RESULTS

The pain construct analysis involved 211 effect estimates from 153 studies and 14 independent variables. High-frequency acupuncture treatment sessions produced larger effects compared to low-frequency sessions [large magnitude, the difference of adjusted SMDs 0.46, 95% confidence interval (CI) 0.07 to 0.84; P=0.02]. The non-pain symptoms construct analysis comprised 323 effect estimates from 231 studies and 15 independent variables. Penetrating acupuncture showed moderately larger effects when compared to non-penetrating acupuncture (0.30, 95% CI 0.06 to 0.53; P=0.01). The function construct analysis included 495 effect estimates from 274 studies and 14 independent variables. Penetrating acupuncture and the flexible acupuncture regimen showed moderately larger effects, compared to non-penetrating acupuncture and fixed regimen, respectively (0.40, 95% CI 0 to 0.80; P=0.05; 0.29, 95% CI 0.06 to 0.53; P=0.01).

CONCLUSIONS

High-frequency acupuncture sessions appear to be a more effective approach to managing painful symptoms. Penetrating acupuncture demonstrated greater effect in relieving non-painful symptoms. Both penetrating acupuncture type and flexible acupuncture regimen were linked to significant treatment effects in function outcomes. Future studies should consider the factors that are significantly associated with the effects of acupuncture in patient-important outcomes.

Placebo Response among Different Types of Sham Acupuncture for Low Back Pain: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Low back pain (LBP) is a prevalent and debilitating condition that poses a significant burden on healthcare systems. Acupuncture has been proposed as a promising intervention for LBP, but the evidence supporting its specific effect is insufficient, and the use of sham acupuncture as a control in clinical trials presents challenges due to variations in sham acupuncture techniques and the magnitude of the placebo effect.

OBJECTIVE

To investigate the magnitude of the placebo response of sham acupuncture in trials of acupuncture for nonspecific LBP, and to assess whether different types of sham acupuncture are associated with different responses.

METHODS

Four databases including PubMed, EMBASE, MEDLINE, and the Cochrane Library were searched through April 15, 2023, and randomized controlled trials (RCTs) were included if they randomized patients with LBP to receive acupuncture or sham acupuncture intervention. The main outcomes included the placebo response in pain intensity, back-specific function and quality of life. Placebo response was defined as the change in these outcome measures from baseline to the end of treatment. Random-effects models were used to synthesize the results, standardized mean differences (SMDs, Hedges'g) were applied to estimate the effect size.

RESULTS

A total of 18 RCTs with 3,321 patients were included. Sham acupuncture showed a noteworthy pooled placebo response in pain intensity in patients with LBP [SMD -1.43, 95% confidence interval (CI) -1.95 to -0.91, I2=89%]. A significant placebo response was also shown in back-specific functional status (SMD -0.49, 95% CI -0.70 to -0.29, I2=73%), but not in quality of life (SMD 0.34, 95% CI -0.20 to 0.88, I2=84%). Trials in which the sham acupuncture penetrated the skin or performed with regular needles had a significantly higher placebo response in pain intensity reduction, but other factors such as the location of sham acupuncture did not have a significant impact on the placebo response.

CONCLUSIONS

Sham acupuncture is associated with a large placebo response in pain intensity among patients with LBP. Researchers should also be aware that the types of sham acupuncture applied may potentially impact the evaluation of the efficacy of acupuncture. Nonetheless, considering the nature of placebo response, the effect of other contextual factors cannot be ruled out in this study. (PROSPERO registration No. CRD42022304416).