Comparative effectiveness of ten traditional Chinese herbal formulas for acute exacerbation of chronic obstructive pulmonary disease: a systematic review and Bayesian network meta-analysis of 131 randomized controlled trials

Enze Yu^1,2Chunyan Tian¹Pengna Jiang¹Xingyi Wang^1,2Yuting Yin^1,2Zhuying Li^1*

• ¹First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin, China
• ²Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang Province, China

Background: Traditional Chinese medicine (TCM) has emerged as a valuable adjunctive approach for respiratory diseases, with accumulating evidence supporting its efficacy in Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) management. However, most existing randomized controlled trials (RCTs) and meta-analyses have focused on evaluating single traditional Chinese herbal formulas as an add-on to conventional therapy (CT). The comparative efficacy among these formulas remains uncertain, creating a critical evidence gap that impedes clinical decision-making. Network meta-analysis (NMA) provides a methodological framework to address this limitation by enabling simultaneous comparison of multiple interventions. Methods: RCTs of these ten herbal formulas in combination with CT for the treatment of AECOPD were searched in five English and four Chinese databases. The search covered the period from the date of database inception to August 20, 2024, with a final update performed on July 20, 2025. The risk of bias of the included RCTs was critically assessed using the Cochrane Risk-of-Bias tool for randomized trials, version 2 (RoB 2). Bayesian NMA, pairwise meta-analysis (PMA), meta-regression, subgroup and sensitivity analyses, and publication bias analysis were carried out. The certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results: A total of 131 eligible RCTs involving 13,317 participants were included. Both PMA and NMA demonstrated that all ten herbal formulas combined with CT were more effective than CT alone in treating AECOPD. Based on the ranking results, QQHT, ECSZYQ, and XQL had the highest probability of being the most efficacious interventions in improving lung function (FEV1, FEV1%pred, FEV1/FVC). For the correction of arterial blood gas abnormalities (PaO2, PaCO2), XBCQ, QQHT, and XQL were ranked as the top-ranked interventions. However, the GRADE framework rated the certainty of evidence for NMA and most PMA results as "very low". Conclusion: This study suggests that QQHT and XQL are among the most promising regimens of the ten herbal formulas evaluated for AECOPD management. Nevertheless, the low certainty of evidence mandates that these findings be interpreted with caution. Further high-quality, head-to-head comparative studies are needed to validate these findings.