Table 2.

Reverse derivations of parameters in the life table

Number (i)	Time (Ti)	Death (Di)	Censored (Ci)	Risk patients (Ni)	Survival probability (Pi)	Survival rate (Si)
1	$T_1$	$D_1=N_1\left(1,-,P_1\right)$	$C_1$	$N_1$	$P_1=S_1$	$S_1$
2	$T_2$	$D_2=N_2\left(1,-,P_2\right)$	$C_2$	$N_2=N_1-D_1-C_1$	$P_2=\frac{S_2}{S_1}$	$S_2$
3	$T_3$	$D_3=N_3\left(1,-,P_3\right)$	$C_3$	$N_3=N_2-D_2-C_2$	$P_3=\frac{S_3}{S_2}$	$S_3$
…	…	…	…	…	…	…
i-1	$T_{i-1}$	$D_{i-1}=N_{i-1}\left(1,-,P_{i-1}\right)$	$C_{i-1}$	$N_{i-1}=N_{i-2}-D_{i-2}-C_{i-2}$	$P_{i-1}=\frac{S_{i-1}}{S_{i-2}}$	$S_{i-1}$
i	$T_i$	$D_i=N_i\left(1,-,P_i\right)$	$C_i$	$N_i=N_{i-1}-D_{i-1}-C_{i-1}$	$P_i=\frac{S_i}{S_{i-1}}$	$S_i$

The values of T_i and S_i can be extracted from the KM curve. Based on T_i and S_i, the values of P_i, N_i, and D_i can be calculated. This table demonstrates how to reconstruct the life table through reverse derivation of parameters within the life table