This application may be used at two potential starting time points, i.e., when a clinician encounters: (1) a patient; (2) a patient with urinary catheterization (UC). Four questions should be answered yes as an indication to use this application. First, is the patient's age 20 to 75 years old? Second, is the patient on UC day 0 to 5? Third, is the patient underwent UC removal last 2 d? Fourth, was this application used for the first time in this UC episode? If the last question was answered no, was the risk <0.14?