Table 1.

Mean μ̃₂ and variance ${\stackrel{\sim }{\sigma }}_2^2$ of the observed/imputed values at year 2, and the probability that a one-sample one-sided test of H₀: μ₂ = 0 would be nominally statistically significant at the 0.05 level, for given mean and variance of the 1 and 2-year values (μ₁, ${\sigma }_1^2$, μ₂, ${\sigma }_2^2$), with a sample size of n = 100, 30% of which are missing completely at random at 2-years and are replaced by the values at 1-year. Cases 1 and 5 also provide the type I error probability and power with no missing data.

Case	μ2	${\sigma }_2^2$	μ1	${\sigma }_1^2$	μ̃2	${\stackrel{\sim }{\sigma }}_2^2$	Pr(significant)
1	0	20	0	20	0	20	0.05
2	0	20	−1	20	−0.3	20.21	0.010
3	0	20	1	20	0.3	20.21	0.164
4	0	20	1	30	0.3	23.21	0.153
5	1	20	1	20	1	20	0.723
6	1	20	−1	20	0.4	20.84	0.221
7	1	20	0	20	0.7	20.21	0.465
8	1	20	2	20	1.3	20.21	0.894
9	1	20	2	30	1.3	23.21	0.854