Number at risk

The number at risk gives, for a time t, how many people are still being observed and have not yet experienced the event. In publications it appears as a table below the chart and shows how many people support the curve at each point. It falls through events and through censoring.

Example: At 800, 6 people are still at risk: the curve rests on very few people there.

Caution: Where only a few are still at risk (below about 10), the curve jumps strongly at every event and the interval is wide. Do not over-interpret such stretches.