Exploration of quantitative-effectiveness association between acupuncture temporal parameters and stable chronic obstructive pulmonary disease: A systematic review and dose-response meta-analysis of randomized controlled trials

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is a globally common chronic respiratory disease with a high morbidity and mortality rate. Acupuncture has been proven effective for COPD. A dose-response meta-analysis was conducted to assess the correlation between the acupuncture temporal parameters(session, frequency, and duration) and its effectiveness in patients with stable COPD. Methods: Acupuncture randomized controlled trials on COPD were searched in eight databases from their inception to June 2023. The ''doses'' were defined as the acupuncture session, frequency, and duration. The outcomes mainly included Forced Expiratory Volume in one-second rate (FEV1%) and Six-minute Walking Distance (6MWD). The assessment of bias risk and literature quality were conducted independently using the Cochrane risk of bias tool and the Standards for reporting interventions in clinical trials of acupuncture. The dose-response relationship was modeled using robust error element regression, and meta-analysis was operated by R 4.3.1 and Stata 15.0. The protocol was registered in PROSPERO with the registration number CRD42023401406. Result: Out of 1669 records, 17 RCTs with 1165 participants were finally included in the meta-analysis. There was notable heterogeneity among the studies, but sensitivity analysis demonstrated good robustness. The findings revealed a significant improvement in the following outcomes for stable COPD patients in the acupuncture group: FEV1% (MD=3.50, 95%CI: 2.05–4.95), 6MWD (MD=47.39, 95%CI: 29.29–65.50), St. George's respiratory questionnaire (SGRQ; MD=−8.25, 95%CI: −11.38 to −5.12); COPD assessment test (CAT; MD=−2.91, 95%CI: −3.99 to −1.83). The relationship between the acupuncture session, duration, and FEV1%, 6MWD followed a ''Λ'' curve pattern, while the relationship between acupuncture frequency and FEV1%, 6MWD exhibited logarithmic growth. Firstly, After 12 acupuncture sessions, FEV1% and 6MWD increased by 7.06% (95%CI: 4.56–9.55) and 36.28 m (95%CI: 20.37–52.20), respectively. The peak improvement in FEV1% and 6MWD was observed after 18 acupuncture sessions (MD=7.89, 95% CI: 5.33–10.45) and 45 sessions (MD=125.43, 95% CI: 72.80–178.07) each. Additionally, weekly acupuncture resulted in a 4.14% improvement in FEV1% (95% CI: 2.55–5.72) and a 42.49 m increase in 6MWD (95%CI: 17.16–67.81). Notably, the maximum effects on FEV1% and 6MWD improvement were achieved with different acupuncture frequencies, specifically three times a week (MD=6.00, 95% CI: 5.34–6.66) and once a day(MD=112.41, 95% CI: 77.27–147.56), respectively. Furthermore, after a 28-day duration of acupuncture treatment, FEV1% increased by 4.74% (95% CI: 3.73–5.75) and 6MWD increased by 47.34 m (95%CI: 22.01–72.67). During 60 days of acupuncture treatment, the FEV1% and 6MWD improvement reached their highest levels at 8.76% (95% CI: 7.05–10.47) and 88.06 m (95% CI: 45.96–130.16), respectively. Conclusion: Acupuncture was effective in improving FEV1%, 6MWD, SGRQ, and CAT in patients with stable COPD. There was a dose-response relationship between the time parameters of acupuncture (session, frequency, and duration) and the efficacy of COPD treatment (FEV1% and 6MWD). The minimal clinically important difference could be achieved after 12 acupuncture sessions. Acupuncture with a medium-frequency (2–3 times per week) over 60 days may result in the greatest improvement in FEV1%, while higher-frequency acupuncture (5–7 times per week) for 2 months may lead to the maximum improvements in 6MWD. It indicated that the optimal acupuncture duration for different indicators remains consistent, while the optimal frequencies may differ. To confirm these results, it is necessary to conduct multicenter, large-scale randomized controlled trials. Ethics and dissemination: Ethical approval is not required for literature-based studies. The results will be published in peer-reviewed journals or conferences.