Skip to main content
. Author manuscript; available in PMC: 2015 Mar 9.
Published in final edited form as: J Biopharm Stat. 2014;24(3):634–648. doi: 10.1080/10543406.2014.888444

Table 2.

Monte Carlo results (based on 500 replicates): Linear regression with missing covariate where N = 200, X1 ~ N(2,1), X2 ~ N(2,1), Y ~ N(b0 + b1 * X1 + b2 * X2, 4), missing rate = 0.33, Spearman correlation coefficient between X1 and X2: 0.00, Spearman correlation coefficient between X1 and Y: 0.29 and Spearman correlation coefficient between X2 and Y: −0.29

b0 = 10.000
 b1 = 1.333
 b2 = −1.333
Method Esta SDb SEc CRd Est SD SE CR Est SD SE CR
FO 10.001 0.827 0.856 95.4 1.354 0.290 0.286 96.0 −1.358 0.293 0.286 95.4
CC 10.248 0.873 0.896 95.6 1.049 0.308 0.313 85.0 −0.368 0.350 0.348 22.2
IPWDR12 10.447 1.226 1.608 89.6 1.155 0.555 0.616 87.6 −1.382 0.338 0.459 94.2
IPWDR21 9.969 0.996 1.142 96.6 1.378 0.422 0.450 95.4 −1.360 0.334 0.345 93.8
IPWDR22 9.941 1.200 1.241 95.6 1.379 0.512 0.510 93.4 −1.336 0.340 0.357 94.0
NNMIB12 M1: misspecified; M2: correctly specified
(3,0.8,0.2)e 10.475 0.966 1.085 94.2 1.122 0.381 0.419 93.8 −1.373 0.316 0.321 95.4
(3,0.5,0.5) 10.335 1.044 1.134 94.8 1.173 0.421 0.439 95.2 −1.343 0.317 0.327 94.8
(3,0.2,0.8) 10.263 1.103 1.196 94.6 1.191 0.447 0.469 96.0 −1.313 0.318 0.329 95.8
(5,0.8,0.2) 10.552 0.926 1.068 93.6 1.085 0.359 0.410 94.2 −1.380 0.313 0.317 95.4
(5,0.5,0.5) 10.418 0.991 1.100 94.4 1.136 0.395 0.425 93.8 −1.352 0.315 0.322 95.6
(5,0.2,0.8) 10.320 1.053 1.153 95.0 1.165 0.417 0.450 95.2 −1.320 0.312 0.321 96.2
NNMIB21 M1: correctly specified; M2: misspecified
(3,0.8,0.2) 10.121 1.061 1.096 94.8 1.296 0.436 0.435 93.6 −1.353 0.318 0.308 94.4
(3,0.5,0.5) 10.219 1.041 1.075 94.0 1.254 0.425 0.423 94.0 −1.368 0.319 0.311 94.6
(3,0.2,0.8) 10.393 0.979 1.049 94.0 1.176 0.396 0.409 92.8 −1.388 0.318 0.311 94.4
(5,0.8,0.2) 10.162 1.016 1.071 94.8 1.277 0.415 0.424 94.0 −1.359 0.314 0.304 94.8
(5,0.5,0.5) 10.274 0.995 1.061 94.2 1.228 0.406 0.419 95.2 −1.372 0.313 0.308 95.0
(5,0.2,0.8) 10.463 0.940 1.043 94.8 1.145 0.375 0.409 94.8 −1.396 0.315 0.308 94.8
NNMIB22 M1: correctly specified; M2: correctly specified
(3,0.8,0.2) 10.078 1.094 1.136 95.2 1.310 0.453 0.456 93.8 −1.338 0.320 0.308 94.0
(3,0.5,0.5) 10.083 1.143 1.165 93.8 1.299 0.470 0.467 93.6 −1.328 0.323 0.313 94.8
(3,0.2,0.8) 10.116 1.152 1.193 93.6 1.268 0.472 0.473 93.8 −1.311 0.323 0.319 94.8
(5,0.8,0.2) 10.110 1.054 1.109 95.0 1.295 0.435 0.442 93.2 −1.344 0.313 0.305 94.6
(5,0.5,0.5) 10.130 1.090 1.131 95.2 1.277 0.446 0.450 94.6 −1.333 0.317 0.309 95.0
(5,0.2,0.8) 10.173 1.080 1.155 95.4 1.242 0.435 0.455 96.0 −1.319 0.315 0.313 95.0
a

Average of 500 point estimates.

b

Empirical standard deviation of 500 point estimates.

c

Average of 500 estimated standard errors.

d

Coverage rate of 500, 95% confidence intervals.

e

(NN, w1, w2).