本文探讨了生存分析模型的特征，包括随时间降低的存活可能性，从1开始至0结束的趋势，以及右删失、研究结束删失和失访删失的概念。介绍了生存率估计的方法，如假设右删失患者立即死亡或永不死亡，以及使用条件概率的Kaplan-Meier估计方法。
Survival Estimate function on the whole population
一. Survival Model feature
a) Decreasing survive possibility as time goes on. b) Start at 1 and end at 0.
二. Censoring (实验终止)
- Right censoring: the timed the event is only known to exceed a
certain value(18+) - The end-of-study censoring （the i_2 in the following figure）
- Lost-to-follow-up censoring（the i_3 in the following figure）
三. Estimate method
- assume the right censor patient die immediately(18+——18)
- assume the right censor patient never die(18+——infinite)
- use conditional probability(Kaplan-Meier Estimation):
The probability of survival past 25
=P(t>25)
=P(t>=26,t>=25,…,t>=2,t>=1,t>=0)
=P(t>=26|t>=25)…P(t>=1|t>=0)P(t>=0)
=P(t>=26|t>=25)…P(t>=1|t>=0)
=[1-P(t=25|t>=25)]…[1-P(t=0|t>=0)]
四. The result of the estimate
##New Estimate refer to the one that use conditional probability
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