Efficacy and safety of Buyang-Huanwu-Tang (Boyang-Hwano-Tang) in patients with vascular dementia: A systematic review and meta-analysis.

Background: Buyang-Huanwu-Tang (Boyang-Hwano-Tang, BHT) is a widely used traditional Chinese herbal medicine for treating ischemic stroke in South Korea and China. Its efficacy in vascular dementia has been reported. There has been no comprehensive systematic review of BHT for vascular dementia.

Methods: We searched 15 electronic databases from inception to November 25, 2021. We included only randomised controlled clinical trials. Studies that used BHT alone or with Western medicine were included. Two independent reviewers conducted the screening, data extraction, and the Cochrane risk of bias and quality of evidence assessment. A meta-analysis was performed.

Results: A total of 18 eligible trials with 1254 participants were included. Of these, 15 were included in the meta-analysis. The pooled results suggested that BHT alone (mean difference [MD] 1.31; 95% confidence interval [CI] -2.94 to 5.56; P = 0.55) was similar to Western medicine alone in terms of the Mini-Mental State Examination(MMSE). Additive BHT therapy showed a significant improvement in the MMSE (MD 1.42; 95% CI 0.28 to 2.56; P = 0.01), Hasegawa Dementia Scale score (MD 3.91; 95% CI 2.87 to 4.94; P < 0.001) and total effective rate (risk ratio 1.35; 95% CI 1.20 to 1.52; P < 0.001). The overall risk of bias was unclear or high. The quality of evidence was very low to moderate. Only four studies reported minor or no adverse events.

Conclusions: The results support the clinical use of BHT for the improvement of cognitive function in patients with vascular dementia. The methodological quality of the included studies was relatively poor. Therefore, further rigorously designed trials are required.