Efficacy of Alendronate for Preventing Collapse of Femoral Head in Adult Patients with Nontraumatic Osteonecrosis

Figure 2

Graph showing comparing collapse rates prevention between alendronate and control groups in all the included patients. Chen’s study was found to be the outlier as its confidence interval of the estimated effect size did not well overlap with the pooled overall effect size. Without the outlier, the overall effect favours alendronate over control () with minimal heterogeneities (). The size of each square is proportional to the weight of the study. Z: value of weighted test for overall effect, CI: confidence interval, df: degree of freedom, test statistic.