. Author manuscript; available in PMC: 2014 Jun 30.

Published in final edited form as: Stat Med. 2012 Dec 12;32(14):2390–2405. doi: 10.1002/sim.5691

Table 1.

GEE estimates of parameters, standard errors, and type I error rates based on Wald and score tests, along with empirical standard errors and type I error rates for ZIP under complete data from 1,000 MC simulations.

Simulation summary for ZIP under complete data
β_u₀ = −1, β₀ = 1, β₁ = 1
Parameter	Mean	Standard errors		Type I error for H₀ : β₁ = 1
		WGEE	Empirical	Wald		Score
				WGEE	Empirical
Sample size of 50
β_u ₀	−1.052	0.363	0.385
β ₀	1.000	0.090	0.100
β ₁	0.998	0.039	0.048
				0.095	0.061	0.045
Sample size of 100
β_u ₀	−1.021	0.252	0.256
β ₀	1.000	0.063	0.067
β ₁	0.999	0.027	0.031
				0.076	0.052	0.054
Sample size of 200
β_u ₀	−1.012	0.177	0.176
β ₀	0.999	0.044	0.046
β ₁	1.000	0.019	0.021
				0.065	0.042	0.042