Note: ″*″Dependent variable: severity of AD (Mild, Moderate, Severe), the association between complicated factor and severity of AD was examined separately by mix-effect two-level (level one: individual; level two: region) ordered logistic regression after adjusting for gender, marital status, age on disease set, educational level and comorbidity. An LR tests comparing the model with the one-level model favored the random-intercept model with P <0.05 for all the analysis.