Effectiveness of standardized ginkgo biloba extract on cognitive symptoms of dementia with a six-month treatment: a bivariate random effect meta-analysis

Introduction: The objective of this study is to take into consideration the influence of baseline risk on the treatment effect and evaluate the effectiveness of standardized Ginkgo biloba extract (GbE) on cognitive symptoms of dementia with the treatment period of approximately 6 months. Methods: We systematically searched the literature to identify all randomized placebo-controlled clinical trials (English language) of GbE in the treatment of dementia. Data were extracted from selected trials and combined with standard meta-analysis methods. A bivariate meta-analysis was carried out to further estimate the effect size of GbE. Results: The random effect estimate of standard mean difference (SMD) between GbE and placebo groups of 6 selected trials was - 0.89 (95% CI -1.82 to 0.04) in the assessment of cognitive function. Bivariate random effect estimate of difference of change in ADAS-cog scores was -2.65 (95% CI -4.53 to -0.76), which showed a significant difference in favor of GbE. Conclusion: Considering baseline risk in the assessment of treatment effect, GbE was found to be effective for cognitive functions in dementia with the treatment of 6 months.