Ankylosing spondylitis (AS), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are the most common rheumatic diseases dealt with rheumatologists in Taiwan. In previous studies, the 3 diseases all have broad impacts on health-related quality of life of patients and drive enormous economic burden on patients and society. The objective of this study is to compare health-related quality of life and disease-related costs between patients with the 3 different diseases. We will invite at least 100 patients with AS, RA or SLE respectively who are regularly followed in the outpatient clinic of the Division of Rheumatology at Taichung Veterans General Hospital (VGHTC) to participate in the study. Patients who have cognitive impairment, who are older than 65 years old or younger than 18 years old, who have overlapping syndrome of any 2 of the 3 rheumatic diseases (eg. RA overlapping with SLE) or who have visited rheumatologists in the outpatient clinics at VGHTC for less than 4 times in 2008 will be excluded. Patients who agree to take part will attend a comprehensive clinical examination in the outpatient department. Patients will complete a questionaire including demographic and disease characteristics, and health-related quality of life at the time of survey. The questionaires about disease-related costs will be completed once per quarter throughout 2009. The four questionaires about costs will be given at the time of initial survey and will be returned by returned by mail or in the following outpatient clinics visits every 3 months in 2009. The result of this study will help patients to realize their own health-related quality of life and disease-related costs and help government in Taiwan to realize the socioeconomic burden of the 3 common rheumatic diseases and to allocate health care resources more properly in the future.