Baseline neuropsychiatric symptoms are effect modifiers in <ce:italic>Ginkgo biloba</ce:italic> extract (EGb 761®) treatment of dementia with neuropsychiatric features. Retrospective data analyses of a randomized controlled trial
Previous studies suggested that EGb 761® may be more effective when dementia is associated with neuropsychiatric features. To find out whether treatment effects correlate with neuropsychiatric symptom burden at baseline, retrospective analyses of data from a 24-week randomized, placebo-controlled, double-blind clinical trial of EGb 761® (240 mg once daily) were performed. 410 outpatients with mild to moderate AD, VaD or AD with cerebrovascular disease, each associated with neuropsychiatric features, were enrolled. Patients scored 5 or above on the NPI, with at least one item score being ≥3, and between 9 and 23 on the SKT cognitive test battery. Correlations between the NPI composite score at baseline and other efficacy variables were calculated. Regression analyses with the NPI composite score as regressor and efficacy variables as dependent variables were performed. Correlations between changes from baseline and NPI baseline scores were weak to modest, but conspicuously different between active drug and placebo groups. The slopes of the regression lines for the EGb 761® and the placebo groups showed qualitative and statistically significant differences: With increasing NPI baseline scores there was faster deterioration in the placebo group and thus more net benefit from treatment for the EGb 761® group.