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. Author manuscript; available in PMC: 2016 Sep 7.
Published in final edited form as: Biometrics. 2016 Feb 17;72(3):986–994. doi: 10.1111/biom.12492

Table 1. Simulation results for the mean ratio (exposed vs unexposed), using the APV and the derived mean estimation from a latent (conventional) log-logit model, and the direct mean estimation from a marginal log-logit working model, with data generated from ZINB models.

Latent log-logit working model Marginal log-logit working model

APV estimation Derived marginal mean estimation Direct marginal mean estimation



True MR n EMR RB(%) MSE CP(%) EMR RB(%) MSE CP(%) AIC EMR RB(%) MSE CP(%) AIC
Data generated from a ZINB model with a latent mean
0.543 100 0.547 0.743 0.017 92.7 0.545 0.314 0.019 99.8 434.14 0.548 0.915 0.018 92.6 434.17
200 0.547 0.740 0.008 94.8 0.546 0.452 0.008 98.6 863.40 0.547 0.675 0.008 95.1 863.44
400 0.546 0.546 0.005 92.1 0.545 0.281 0.005 99.9 1716.61 0.546 0.480 0.005 93.4 1716.68
1000 0.545 0.301 0.002 94.2 0.543 0.024 0.002 >99.9 4285.21 0.544 0.224 0.002 95.3 4285.30

Data generated from a ZINB model with a marginal mean
0.607 100 0.625 3.086 0.021 94.7 0.625 3.071 0.045 96.7 475.74 0.626 3.281 0.021 94.7 475.72
200 0.614 1.288 0.011 93.1 0.613 1.003 0.011 99.9 945.35 0.614 1.192 0.011 93.3 945.35
400 0.609 0.435 0.005 94.7 0.608 0.254 0.005 >99.9 1883.04 0.608 0.395 0.005 94.5 1883.00
1000 0.608 0.228 0.002 95.6 0.607 0.055 0.002 >99.9 4704.47 0.607 0.146 0.002 95.6 4704.40

n/2 is sample size per group