IAI Actuarial Core Principles · Risk Modelling and Survival Analysis · Estimation procedures for lifetime distributions
In the Kaplan-Meier estimator, a life censored at time t, where a death also occurs at the same time t, is normally treated in which way?
The censored life is kept in the risk set at the death time. The usual convention treats censoring as happening just after deaths at the same time, so the life counts in the denominator but not as a death.
- AAs having died just before t, so removed from the risk set
- BAs being in the risk set at t, since censoring is assumed to occur just after deaths at that timeCorrect
- CAs not contributing at all to the data
- DAs left truncated at t
- As having died at t, adding to the death count
Explanation
Standard convention places censoring just after deaths at the same time, so the censored life remains in the risk set for that death time. This slightly lowers each hazard estimate relative to removing the life earlier.
Did you get it right without looking?
One question tells you little. A timed set on Estimation procedures for lifetime distributions shows your real accuracy, how long you take and where you lose marks.
More Estimation procedures for lifetime distributions questions
- When maximising the Cox partial likelihood in the presence of tied death times, which statement is correct about the methods of handling tie…
- In a study of policyholder lifetimes, a life is observed from age 40 until the study ends at age 52, and is still alive at that point. Which…
- In a Cox model with a single binary covariate z (1 = smoker, 0 = non-smoker), the estimated coefficient is β̂ = 0.405. Taking e^0.405 ≈ 1.5,…
- In a Nelson-Aalen calculation, a life is censored at time 5 and a death occurs at time 5 for another life. By the standard convention, how i…
- Which statement about the Kaplan-Meier estimate of the survival function is correct?
- Ten lives are observed from birth under an exponential model with force of mortality μ. Four die, at times 2, 3, 5 and 6 years. The other si…