Check your understanding
Quiz
You have worked through time-to-event analysis end to end: what censoring really means, the Kaplan-Meier curve and the log-rank test, the Cox model and its hazard ratio, checking the proportional-hazards assumption, committing to a parametric shape, handling competing risks with cumulative incidence, and scoring a survival model honestly. This quiz checks what stuck. The last two steps are live R you can run.
Question 1 of 10
What a censored row means
A patient enrolls, attends every visit, and is still alive when the study closes at 18 months. Their row reads time = 18, status = 0. What does it tell you about their survival time?
Correct: right-censoring means the event had not happened by last contact, so all you know is T > 18. That "at least" is real, usable information.
You saw that they survived at least 18 months, which constrains the estimate; that is exactly what Kaplan-Meier uses.