Table 3.
Large-sample robustness of the assumed Gaussian random effects (GRE) model to the true dependence structure between tests given by the finite mixture (FM) model
r | η1 | Estimator (misspecified model) | Expected log-likelihood* | |||
---|---|---|---|---|---|---|
SENS* | SPEC* | EFM[log LFM] | EFM[log LGRE] | |||
0 | .2 | .41 | .45 | .92 | −2.24106 | −2.24106 |
.02 | .21 | .71 | .90 | −2.24327 | −2.24374 | |
.2 | .20 | .74 | .90 | −2.26317 | −2.26454 | |
1 | .20 | .75 | .90 | −2.35160 | −2.35410 | |
0 | .5 | .15 | .77 | .86 | −2.10467 | −2.10476 |
.02 | .16 | .75 | .87 | −2.10796 | −2.10973 | |
.20 | .18 | .76 | .89 | −2.13749 | −2.14648 | |
1 | .20 | .76 | .90 | −2.26875 | −2.28668 |
NOTE: Verification is independent of Yi, and r denotes the proportion of random samples verified [i.e., P(Vi = 1) = r]. The true model is an FM model with η0 = .2, Pd = .20, SENS = .75, and SPEC = .9 for differing r and η1 and with J = 5. Asymptotic bias for sensitivity and specificity is SENS* ′ SENS and SPEC* ′ SPEC, respectively.
Expected individual contribution to the log-likelihood.