1. Institute of Public Health; School of Medicine, National Yang-Ming University; Taipei City Taiwan
2. Department of Statistics; Tunghai University; Taichung City Taiwan
3. Division of Allergy, Immunology and Rheumatology; Department of Medicine, Chung Shan Medical University Hospital; Taichung City Taiwan
4. Division of Allergy; Immunology and Rheumatology, Chung Shan Medical University Hospital; Taichung City Taiwan
5. Department of Statistics; Oklahoma State University; Stillwater OK 74074 USA