Table 3.

Model‐Estimated Parameter Estimates and Standard Errors from the One‐Part GLM, Uncorrelated Two‐Part GLMs, and Correlated Marginalized Two‐Part Random Effects Model (REM)

Coefficient	One‐Part GLMa	Uncorrelated Two‐Part GLMsb		Correlated Marginalized Two‐Part REMc
	Estimate of Effects on log E(Costij) (SE)	Estimate of Effect on $\text{PR}({\text{Cost}}_{\mathit{ij}}>0)$ (SE)	Estimate of Effect on $logE({\text{Cost}}_{\mathit{ij}}|{\text{Cost}}_{\mathit{ij}}>0)$ (SE)	Estimate of Effect on $\text{Pr}({\text{Cost}}_{\mathit{ij}}>0|{\mathbf{b}}_i)$ (SD)	Estimate of Effect on log E(Costij) (SD)
Intercept	6.92 (0.05)	1.24 (0.06)	7.14 (0.05)	2.13 (0.12)	6.24 (0.05)
Year2001	0.05 (0.05)	0.19 (0.06)	0.006 (0.05)	0.31 (0.11)	0.13 (0.05)
Year2002	0.07 (0.06)	0.42 (0.07)	0.0005 (0.06)	0.83 (0.14)	0.23 (0.05)
Year2003	0.17 (0.05)	0.22 (0.07)	0.12 (0.06)	0.65 (0.17)	0.28 (0.05)
MUSTPAY	−0.24 (0.07)	−0.65 (0.08)	−0.09 (0.07)	−1.06 (0.14)	−0.34 (0.07)
MUSTPAY*Year2001	0.02 (0.08)	−0.05 (0.09)	0.04 (0.08)	0.005 (0.14)	−0.02 (0.07)
MUSTPAY*Year2002	−0.04 (0.09)	−0.17 (0.10)	−0.03 (0.09)	−0.15 (0.16)	−0.20 (0.07)
MUSTPAY*Year2003	−0.17 (0.09)	−0.14 (0.09)	−0.14 (0.09)	−0.34 (0.18)	−0.32 (0.07)

^aFit via GEE with proportional mean–variance, log link, and unstructured correlation.

^bFit via GEE using a binomial variance and logit link for the first component and proportional mean–variance and log link for the second. Unstructured correlation was used for both components.

^cFit via MCMC with noninformative prior distributions; note estimates from the marginalized model are posterior means and standard deviations.