Skip to main content
. Author manuscript; available in PMC: 2015 Jul 30.
Published in final edited form as: Stat Med. 2014 Mar 17;33(17):3013–3028. doi: 10.1002/sim.6137

Table 2.

Treatment effect (log odds ratio) estimates from a simulation study of multiple imputation of binary data using multiple models. One hundred models, 2 imputations within each model. Each row represents a different assumption regarding the control group missing data mechanism. Treatment group missing data are assumed to be MAR with no uncertainty throughout.

Ignore Assump. Uncertainty Mult.* Mean Mult.* Ratio** Bias RMSE Cvg. Width of CI γ̂ γ̂w γ̂b
γ^bγ^
MAR None log(1) log(1) 0.66 0.75 59.1 1.47 0.60 0.60 0.00 0.00
Mild log(1) log(2) 0.66 0.75 62.8 1.55 0.64 0.60 0.03 0.06
Moderate log(1) log(3) 0.66 0.75 67.9 1.65 0.68 0.60 0.08 0.12
Ample log(1) log(4) 0.66 0.75 72.6 1.74 0.71 0.60 0.11 0.16
Weak NMAR None log(2) log(1) 0.22 0.42 90.6 1.47 0.58 0.59 0.00 0.00
Mild log(2) log(2) 0.22 0.42 91.9 1.53 0.62 0.59 0.03 0.05
Moderate log(2) log(3) 0.23 0.43 93.2 1.62 0.66 0.59 0.07 0.11
Ample log(2) log(4) 0.23 0.43 94.9 1.70 0.69 0.59 0.10 0.15
Strong NMAR None log(3) log(1) −0.01 0.36 94.9 1.46 0.56 0.57 0.00 0.00
Mild log(3) log(2) −0.01 0.36 95.5 1.51 0.59 0.57 0.03 0.05
Moderate log(3) log(3) 0.00 0.36 97.0 1.58 0.63 0.56 0.06 0.10
Ample log(3) log(4) 0.00 0.36 97.7 1.65 0.65 0.56 0.09 0.14
Misspec. NMAR None log(.5) log(1) 1.10 1.16 14.0 1.48 0.60 0.60 0.00 0.00
Mild log(.5) log(2) 1.10 1.16 16.2 1.55 0.63 0.60 0.03 0.05
Moderate log(.5) log(3) 1.10 1.16 20.7 1.64 0.67 0.60 0.07 0.11
Ample log(.5) log(4) 1.10 1.16 24.2 1.72 0.70 0.60 0.10 0.15

Mult: multiplier; RMSE: root mean squared error; Cvg: coverage

*

Multipliers drawn from a Normal distribution;

**

Multiplier SD= mult. ratio/3.92