Introduction
Among community-dwelling older adults, inadequate health literacy was independently linked to poorer physical and mental health (Until now, over 150 instruments of health literacy have been developed, ranging from traditional tools focused on individual skill and health education to updated instruments from multidimensional perspectives (CRHLS might be unsuitable for older adults in China. Firstly, the time consuming might be a huge challenge for older adults. Most of the young and middle-aged adults might spend about 30 min to complete measurement (Item response theory (IRT) was a complex approach that attempted to explain the relationship between latent traits (unobservable characteristic or attribute) and their manifestations (i.e., observed outcomes, responses or performance) (Because that the level of education and cognitive status were the important factors related to the health literacy in previous studies (Therefore, the purpose of this study was to simplified CRHLS based on IRT and DIF methods to form a more suitable instrument of health literacy for the Chinese older adults, and further assess the reliability and validity of simplified version.