Relationship between male-to-female ratio and the prevalences of ADHD among children and adolescents in Spain. Meta-regression analysis. Note: The size of the bubble is inversely related to the variance of the study. The solid line represents the linear regression (male-to-female ratio as the meta-independent variable). The shaded area corresponds to the confidence intervals of the prediction.
Catalá-López et al. BMC Psychiatry 2012 12:168 doi:10.1186/1471-244X-12-168