Research Article

A Two-Stage Joint Model for Nonlinear Longitudinal Response and a Time-to-Event with Application in Transplantation Studies

Table 3

Bias and residual mean squared error (RMSE) for the method with true 𝜙 𝑖 (GS), Empirical Bayes estimates 𝜙 𝑖 (Plug-in), sampled 𝜙 𝑖 , and fully Bayesian approach.

7 time points
% censoring 20 40

𝜎 0.5

𝛾 1 𝛾 2 𝛾 3 𝛾 1 𝛾 2 𝛾 3
GS 0.00 (0.04) −0.02 (0.03) 0.01 (0.03) −0.01 (0.04) 0.02 (0.04) −0.02 (0.04)
plug-in −0.05 (0.06) −0.04 (0.05) 0.06 (0.07) −0.08 (0.09) −0.04 (0.05) 0.12 (0.12)
sampling −0.04 (0.05) 0.03 (0.08) 0.02 (0.07) −0.05 (0.11) −0.02 (0.06) 0.03 (0.10)
Bayesian −0.03 (0.04) −0.02 (0.04) 0.01 (0.02) −0.01 (0.04) −0.02 (0.04) 0.02 (0.07)

𝜎 1

GS 0.04 (0.05) 0.04 (0.07) −0.03 (0.07) −0.05 (0.09) −0.04 (0.06) −0.03 (0.05)
plug-in −0.07 (0.08) −0.08 (0.09) 0.07 (0.09) −0.10 (0.12) −0.08 (0.09) 0.08 (0.11)
sampling −0.07 (0.09) −0.06 (0.10) −0.02 (0.11) −0.05 (0.12) 0.05 (0.11) −0.03 (0.12)
Bayesian 0.01 (0.03) 0.05 (0.06) −0.03 (0.07) 0.05 (0.06) 0.04 (0.06) −0.04 (0.07)

𝜎 5

GS 0.04 (0.06) 0.05 (0.06) 0.04 (0.08) 0.05 (0.10) 0.01 (0.05) −0.02 (0.06)
plug-in −0.09 (0.10) −0.10 (0.11) 0.08 (0.11) −0.20 (0.22) −0.21 (0.22) 0.14 (0.18)
sampling 0.08 (0.13) 0.06 (0.12) −0.05 (0.12) 0.07 (0.14) −0.05 (0.13) −0.11 (0.18)
Bayesian 0.09 (0.10) 0.05 (0.09) −0.09 (0.10) −0.09 (0.10) 0.08 (0.12) −0.12 (0.18)

14 time points
% censoring 20 40

𝜎 0.5

𝛾 1 𝛾 2 𝛾 3 𝛾 1 𝛾 2 𝛾 3
GS −0.03 (0.03) 0.00 (0.02) −0.02 (0.03) 0.02 (0.03) −0.03 (0.04) 0.02 (0.04)
plug-in −0.02 (0.03) −0.03 (0.04) 0.05 (0.07) −0.02 (0.04) −0.03 (0.04) 0.05 (0.06)
sampling 0.03 (0.04) 0.02 (0.06) 0.02 (0.07) 0.02 (0.04) 0.04 (0.05) 0.02 (0.08)
Bayesian −0.03 (0.04) −0.02 (0.04) −0.02 (0.04) 0.02 (0.04) 0.03 (0.04) −0.05 (0.06)

𝜎 1

GS −0.03 (0.04) −0.03 (0.04) −0.01 (0.03) 0.00 (0.03) −0.02 (0.04) 0.05 (0.06)
plug-in −0.09 (0.06) −0.05 (0.06) 0.06 (0.07) −0.02 (0.04) −0.04 (0.05) 0.11 (0.11)
sampling 0.04 (0.08) 0.02 (0.08) −0.02 (0.07) −0.02 (0.04) −0.02 (0.08) 0.04 (0.09)
Bayesian −0.03 (0.04) 0.04 (0.05) −0.03 (0.05) 0.02 (0.04) 0.03 (0.05) 0.06 (0.07)

𝜎 5

GS −0.03 (0.04) −0.03 (0.04) 0.01 (0.04) −0.01 (0.04) −0.02 (0.04) 0.05 (0.06)
plug-in −0.05 (0.06) −0.10 (0.11) 0.07 (0.09) −0.10 (0.11) −0.09 (0.10) 0.11 (0.12)
sampling 0.04 (0.09) 0.04 (0.11) −0.05 (0.11) 0.07 (0.12) 0.05 (0.11) −0.06 (0.16)
Bayesian 0.03 (0.05) 0.03 (0.08) −0.05 (0.10) 0.02 (0.04) 0.06 (0.10) −0.09 (0.14)