https://www.selleckchem.com/products/pf-04957325.html The barriers of change management and negative experiences by some institutions with ADs remain a source of concern. Additional, consistent training would be helpful to choose the right adaptation(s) needed for specific clinical trials and for planning appropriately for operational efficiency such as for drug supply management and data management. The perceived barrier of regulatory acceptance also remains a concern, which could be alleviated by additional interaction with agencies and an update of the FDA draft guidance to industry on adaptive designs.BACKGROUND The incidence of vertebral fracture is commonly used as a primary endpoint in randomized clinical trials of pharmaceutical agents for osteoporosis. In order to investigate the impact of ethnic/regional difference in osteoporosis clinical trials on the incidence of vertebral fracture, we examined the correlation between the incidence of vertebral fracture in the placebo group and baseline bone mineral density (BMD), ethnic and regional differences, or other factors by meta-regression analysis. METHODS We studied a total of 21 trials involving 28,425 patients treated with placebo, which were identified through MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials. RESULTS A univariate meta-regression showed a significant correlation between the proportion of subjects experiencing new vertebral fracture and the proportion of Caucasian subjects (coefficient = 0.223, [Formula see text]), and the proportion of subjects with prevalent vertebral fracture (0.161, [Formula see text]). Baseline lumbar spine BMD did not show significant correlations. As a result of multivariate meta-regression analysis with the factors with [Formula see text] by the univariate meta-regression, the proportion of subjects with prevalent vertebral fracture was identified as an influencing factor (0.139, [Formula see text]). CONCLUSIONS The multivariate meta-regression sho