(1) Preparation before data collection: Be familiar with every content of the health information record form to be used, receive the training of investigators, and use the record form for pre-investigation. (2) Make clear the object of investigation. (3) Sign the informed consent form: The informed consent form should be signed voluntarily by the respondents, and the researchers shall not induce or coerce it. (4) Initiate an investigation: usually, the investigation is conducted by direct face-to-face inquiry. Ask questions one by one in the order of the items in the questionnaire and record them.