Table 6.

Alternative Latent Curve Results from Fitting Univariate Dual Change Score Model to Interval and Ordinal Scalings of the Weighted Center for Epidemiologic Studies-Depression (WCESD) Scale (rescaled version of 13 items of Factor 1)

Parameters & Fit	(a) Interval WCESD No AR Change	(b) Interval WCESD AR(1) Change	(c) Interval WCESD Dual Change	(d) Ordinal WCESD* Linear Change	(e) Ordinal WCESD* AR(1) Change	(f) Ordinal WCESD* Dual Change
Fixed Effects
Mean intercept, µ0	1.48 (91)	1.60 (100)	1.47 (103)	=0	=0	=0
Mean slope, µ1	−0.03 (4.3)	=0	−1.48 (−9.1)	−0.46 (2.5)	=0	−0.04 (1.5)
Constant change, α	=1	=0	=1	=1	=0	=1
Proportion change, β	=0	−0.13 (4.0)	0.03 (0.8)	=0	−0.07 (2.0)	0.03 (0.4)
Scaling coefficients, T	=1	=1	=1	0.5, 1.4 2.0, 2.7, 3.6	0.5, 1.4 2.0 2.6, 3.4	0.5, 1.4 2.0 2.7, 3.6
Variable Intercepts, µ	=0	0.18 (3.4)	=0	=0	−0.05 (2.6)	=0
Random Effects
Intercept Variance, σ02	0.57 (20)	0.51 (15)	0.53 (22)	=1	=1	=1
Slope Variance, σ12	0.01 (1.2)	=0	0.56 (17)	0.011 (0.6)	=0	0.10 (0.3)
Common slope-level, σ01	−0.04 (20)	=0	−0.54 (20)	−0.04 (1.1)	=0	−0.30 (0.5)
Unique Variance, ψ2	0.49 (38)	0.44 (19)	0.50 (37)	0.78 (8.8)	0.67 (7.0)	0.77 (9.7)
Residual Variance, σe2	=0	0.06 (2.0)	=0	=0	0.11 (1.7)	=0
Goodness of Fit
Misfit index χ2 / df	31.3 / 8	21.9 / 8	29.2 / 7	13.7 / 17	10.7 / 17	13.8 / 16
Change in fit Δχ2 / Δdf	42.7 / 3	51.1 / 3	1.9/1; −8.3/1	47.3 / 3	50.3 / 3	−0.1/1;−2.9/1
WLSM scaling factor κ	1	1	1	0.772	0.796	0.734
RMSEA ε	0.02	0.02	0.02	0.00	0.00	0.00

Note: Weighted least squares mean (WLSM) estimator based on weighted least squares plus mean adjusted variances. Sample size N=6,942, 15 patterns of incomplete data; Level Only Baseline for the two scalings are WCESD=74./11 with ε=0.03, and WCESD

^*=61./20, m=0.900, ε=0.02; AR = auto-regression; Root Mean Square Error of Approximation = RMSEA.