Application of Seemingly Unrelated Regression in Medical Data with Intermittently Observed Time-Dependent Covariates
Table 4
Simulation results (summary of estimated parameters, bias, and MSE) for intermittent observation of time-dependent covariates (situation 4 from Table 1) with different sample sizes (, and 240).
Parameter (True value)
Method
Sample size = 20
Sample size = 60
Sample size = 120
Sample size = 240
Bias
MSE
Bias
MSE
Bias
MSE
Bias
MSE
(−1.13)
SURCC
−1.002
.13
7.13
−1.14
−.01
1.87
−1.12
.01
.83
−1.13
−.005
.42
MRMCC
−1.01
.13
6.75
−1.17
−.04
1.94
−1.13
.002
.87
−1.14
−.007
.44
SURBOCF
−1.02
.11
7.42
−1.14
−.01
1.88
−1.12
.01
.83
−1.14
−.006
.42
MRMBOCF
−1.03
.10
6.22
−1.16
−.03
1.82
−1.12
.01
.83
−1.14
−.009
.42
SURLOCF
−1.02
.11
7.42
−1.14
−.01
1.88
−1.12
.01
.83
−1.14
−.006
.42
MRMLOCF
−1.03
.10
6.22
−1.16
−.03
1.82
−1.12
.01
.83
−1.14
−.009
.42
(.23)
SURCC
.18
−.05
7.17
.14
−.09
1.88
.21
−.02
.86
.24
.01
.43
MRMCC
.16
−.07
6.32
.12
−.11
1.94
.19
−.03
.89
.23
.004
.44
SURBOCF
.18
−.05
7.59
.14
−.08
1.89
.21
−.02
.86
.25
.01
.42
MRMBOCF
.15
−.08
5.97
.13
−.10
1.81
.20
−.03
.85
.24
.01
.42
SURLOCF
.18
−.05
7.59
.14
−.08
1.89
.21
−.02
.86
.25
.01
.42
MRMLOCF
.15
−.08
5.97
.13
−.10
1.81
.20
−.03
.85
.24
.01
.42
(−.01)
SURCC
−.08
−.07
1.79
−.02
−.009
.47
−.02
−.01
.23
−.01
−.004
.10
MRMCC
−.02
−.01
3.36
.01
.02
.93
−.01
−.004
.45
−.02
−.008
.19
SURBOCF
.04
.05
3.62
−.02
.02
.81
−.01
−.0004
.41
−.02
−.008
.18
MRMBOCF
−.02
−.01
2.76
.009
.02
.76
−.01
−.004
.39
−.02
−.008
.17
SURLOCF
.04
.05
3.62
−.02
.02
.81
−.01
−.0004
.41
−.02
−.008
.18
MRMLOCF
−.02
−.01
2.76
.009
.02
.76
−.01
−.004
.39
−.02
−.008
.17
(−1.12)
SURCC
−1.10
.02
2.27
−1.12
−.005
.57
−1.08
.03
.27
−1.10
.02
.13
MRMCC
−1.13
−.01
2.40
−1.15
−.03
.64
−1.09
.03
.32
−1.10
.02
.15
SURBOCF
−1.11
.006
2.39
−1.12
−.004
.57
−1.08
.03
.27
−1.10
.02
.13
MRMBOCF
−1.14
−.02
1.87
−1.13
−.006
.54
−1.08
.04
.26
−1.10
.02
.13
SURLOCF
−1.11
.006
2.39
−1.12
−.004
.57
−1.08
.03
.27
−1.10
.02
.13
MRMLOCF
−1.14
−.02
1.87
−1.13
−.006
.54
−1.08
.04
.26
−1.10
.02
.13
*Note: , and MRMLOCF represent the estimated parameters from MRM and SUR models under complete case (CC) analysis, baseline observation carried forward (BOCF), and last observation carried forward (LOCF) method, respectively.