Method

Model name

Model description

Parameter Description

Parameter method

Weibull distribution model

F(t) is density function, s(t) is survival number; $\lambda ,\beta$ is control curve shape parameters; t is analysis time

Semiparametric method

Weibull distribution model

$h_{0}t$ is Benchmark risk function; ${\beta }_n$ is overall regression coefficient

Nonparametric method

Kaplan-Meier model

P is estimated survival rate for each time; n is total number of individuals observed; d is number of deaths