A meta-analysis of Chinese herbal medicines for vascular dementia

OBJECTIVE: To investigate the efficacy and safety of Chinese herbal medicines in the treatment of patients with vascular dementia. DATA RETRIEVAL: We retrieved publications from Cochrane Library (2004 to July 2011), PubMed (1966 to July 2011), the Chinese Science and Technique Journals Database (1977 to July 2011), the China National Knowledge Infrastructure (1979 to July 2011), Google Scholar (July 2011), and the Chinese Biomedical Database (1977 to July 2011) using the"Chinese medicine OR Chinese herbal medicine" and "vascular dementia OR mild cognition impair OR multi-infarct dementia OR small-vessel dementia OR strategic infarct dementia OR hypoperfusion dementia OR hemorrhagic dementia OR hereditary vascular dementia". SELECTION CRITERIA: Randomized controlled trials comparing Chinese herbal medicines with placebo/western medicine in the treatment of patients with vascular dementia were included. Diagnostic standards included Diagnostic and Statistical Manual of Mental Disorders-IV, and National Institute of Neurological Disorders and Stroke and Association Internationale pour la Recherché et l’Enseignement en Neurosciences. Two participants independently conducted literature screening, quality evaluation and data extraction. The quality of each trial was assessed according to the Cochrane Reviewers’ Handbook 5.0. MAIN OUTCOME MEASURES: Effective rate, Mini-Mental State Examination scores, Hasegawa Dementia Scale scores, and incidence of adverse reactions. RESULTS: We identified 1 143 articles discussing the effects of Chinese medicine on vascular dementia. Thirty-one of these were included in the analysis. These studies involved a total of 2 868 participants (1 605 patients took Chinese medicine decoctions (treatment group); 1 263 patients took western medicine or placebo). The results of our meta-analysis revealed that Chinese herbal remedies in the treatment group were more efficacious than the control intervention (relative risk (RR)=1.27; 95% confidence interval (CI): 1.18-1.38, P<0.01). Mini-Mental State Examination scores were higher in patients taking Chinese herbal medicines than in those in the control group (weighted mean difference (WMD)=2.83; 95%CI: 2.55-3.12, P<0.01). Patients in the treatment group showed better disease amelioration than those in the control group (Hasegawa Dementia Scale scores; WMD=2.41, 95%CI: 1.48-3.34, P<0.01). There were also considerably fewer adverse reactions among those in the treatment group compared with those in the control group (RR=0.20, 95%CI: 0.08-0.47, P<0.01). CONCLUSION: Chinese herbal medicine appears to be safer and more effective than control measures in the treatment of vascular dementia. However, the included trials were generally low in quality. More well-designed, high-quality trials are needed to provide better evidence for the assessment of the efficacy and safety of Chinese medicines for vascular dementia.