Abstract: [Purpose/Significance] As human beings enter an information-intensive society, massive information extensively and profoundly affects and changes people's lives, and gradually causes social problems such as information rumors and information redundancy. The Internet, as the primary channel for people to obtain information, has become the hardest hit area of information problems. Online health information has a wide range of sources and complex topics, due to its uneven quality, it is difficult for users to distinguish between true and false information, which brings great challenges to people, especially middle-aged and elderly people, in obtaining, selecting and using health information. [Methods/Process] The questionnaire survey method was used to explore the characteristics of health information needs and actual behavior interaction of middle-aged and elderly people from the cognitive perspective and the behavioral perspective, respectively. The questionnaire was conducted in two stages. In the first stage, participants were asked to answer an open-ended question, "What characteristics do you think meet your standard of good health information?" in order to collect the desired health information needs of the subjects. Then, we used the grounded theory analysis method to analyze the text of the subjects' answers to form a unified TSCA ideal health information feature framework. The second round of questionnaire survey was conducted on the basis of the first round of investigation and research, and we designed relevant questions to collect the information of subjects' actual health behavior information according to the established TSCA ideal health information feature framework. [Results/Conclusions] There are four features regarding middle-aged and elderly people's needs for desired health information: information topic, information source, information content and document attribute, that is, we construct the TSCA ideal health information feature framework for middle-aged and elderly people. In the process of actual interaction with health information, middle-aged and elderly people use various information topics and sources, but rarely obtain and use information from professional health sources. The study also found that it is necessary to strengthen the scaffolding role of document attribute in the process of actual interaction with health information among middle-aged and elderly people. In addition, two modes are discovered with regard to the desired health information needs of middle-aged and elderly people: topic and source oriented (TS) and content and attribute oriented (CA), but the desired health information needs are not consistent with the actual behavior of middle-aged and elderly people. The discovery of this difference will help to serve the design of the current health information environment and optimize the development of health information literacy education and training for middle-aged and elderly people from the perspective of information characterization.

Key words: middle-aged and elderly, health information demand, behavioral interaction, TSCA ideal health information feature framework