Table 3.
Simulation results comparing estimators of under various model misspecifications for sample size N=5,000. 1,000 simulations. Estimation methods compared include IPTW, EE, efficient TMLE, and compatible TMLE. Bias and MSE values are averages across the simulations. The estimator standard error should be compared to the efficiency bound, which is 1.10. 95% CI Coverage as determined by bootstrapping is denoted in parentheses for scenarios in which the Z model is misspecified.
| Estimand | Bias | %Bias | 95%CI Cov | MSE | |
|---|---|---|---|---|---|
| M model misspecified, N=5,000 | |||||
| TMLE, compatible | 0.000 | 0.02 | 1.05 | 94.30 | 0.000 |
| TMLE, efficient | 0.000 | 0.02 | 1.05 | 94.30 | 0.000 |
| IPTW | −0.024 | −11.28 | 5.32 | 99.40 | 0.003 |
| EE | 0.000 | 0.08 | 1.05 | 94.20 | 0.000 |
| Y model misspecified, N=5,000 | |||||
| TMLE, compatible | 0.000 | 0.09 | 1.14 | 95.60 | 0.000 |
| TMLE, efficient | 0.000 | 0.09 | 1.14 | 95.60 | 0.000 |
| IPTW | 0.003 | 1.45 | 6.53 | 98.70 | 0.005 |
| EE | 0.000 | 0.06 | 1.19 | 96.10 | 0.000 |
| M and Y models misspecified, N=5,000 | |||||
| TMLE, compatible | 0.096 | 44.90 | 1.06 | 0.00 | 0.009 |
| TMLE, efficient | 0.096 | 44.90 | 1.06 | 0.00 | 0.009 |
| IPTW | −0.024 | −11.28 | 5.32 | 99.40 | 0.003 |
| EE | 0.095 | 44.74 | 1.06 | 0.00 | 0.009 |
| Z models misspecified, N=5,000 | |||||
| TMLE, compatible | 0.001 | 0.28 | 1.16 | 87.50 (92.90) | 0.000 |
| TMLE, efficient | 0.012 | 6.28 | 1.38 | 83.10 (92.60) | 0.001 |
| IPTW | 0.003 | 1.45 | 6.53 | 98.70 | 0.005 |
| EE | 0.001 | 0.26 | 1.16 | 88.30 (92.80) | 0.000 |
| Z and Y models misspecified, N=5,000 | |||||
| TMLE, compatible | 0.066 | 33.64 | 1.16 | 2.60 (47.00) | 0.005 |
| TMLE, efficient | 0.041 | 20.72 | 1.42 | 45.70 (46.90) | 0.002 |
| IPTW | 0.003 | 1.45 | 6.53 | 98.70 | 0.005 |
| EE | 0.071 | 36.09 | 1.23 | 2.10 (38.30) | 0.005 |