In epidemiology, the Lexis diagram is a common way to visualize follow-up studies. Each red line represents a woman and each blue line represents a man. A dot at the right end of a line means that an event (e.g. death) in the person's life. If there is no dot, the person dropped out of the study, but not necessarily because of death. The table by the diagram displays the number of events, patient-years, and their ratio in the chosen age window for women, men, and all.