Table 1:

Simulated percent coverage of single test sample 95% confidence intervals using 7 methods (t-Welch=Welch’s t-test; WMW-HL=Hodges-Lehmann CIs based on Wilcoxon-Mann-Whitney test; Delta=delta method; ZINB-Wald= Wald CIs from the ZINB model; ZINB-LRT= CIs from the ZINB model based on the Likelihood Ratio Test; ZINB-RE Sim1 and Sim2=simulation based methods, Sim1 uses σ_c = 0.2306 always and Sim2 simulates values of σ_c with mean 0.2306). We simulated 1000 data sets from each of twelve scenarios: 4 levels of true TRA (0,20,50, and 80) and each done at 3 levels of true σ_c (σ_c = 0.2306, as estimated in the RCM, as well as at the bounds of a 2000-iteration bootstrap 95% percentile confidence interval (0.1587, 0.3006)).

					ZINB		ZINB-RE
TRA	σc	t-Welch	WMW-HL	Delta	Wald	LRT	Sim1	Sim2
0	0.2306	86.3	83.4	80.1	75.6	78.1	94.7	95.9
20	0.2306	86.9	84.3	80.8	74.5	78.9	95.9	96.7
50	0.2306	85.0	82.5	81.3	78.6	77.2	94.5	95.6
80	0.2306	74.4	76.1	81.3	81.3	81.3	94.7	96.3
0	0.1587	91.0	89.0	88.6	84.9	86.0	98.7	99.2
20	0.1587	90.7	87.2	88.1	84.8	87.4	98.0	98.7
50	0.1587	88.9	87.8	88.7	84.7	87.4	98.5	98.7
80	0.1587	78.7	81.1	87.6	87.0	86.8	98.3	98.2
0	0.3006	79.3	75.3	71.8	69.2	71.4	90.4	91.8
20	0.3006	82.0	77.4	74.3	69.1	71.9	92.2	93.2
50	0.3006	78.8	74.9	73.3	68.5	72.2	90.8	92.4
80	0.3006	73.2	73.4	75.6	72.7	72.5	91.2	91.9