. 2021 Mar 22;9(3):297. doi: 10.3390/vaccines9030297

Table 3.

Measurement invariance testing across subsamples in the structure of the Drivers of COVID-19 Vaccination Acceptance Scale (DrVac-COVID19S).

Model (Subsamples)	Nine-Item DrVac-COVID19S		12-Item DrVac-COVID19S
Fit Indices	One-Factor	Four-Factor	One-Factor ^a	Four-Factor ^a
Configural (Taiwan vs. China)
χ² (df)/p-value	482.57 (50)/<0.001	207.81(40)/<0.001	1171.60 (98)/<0.001	771.18 (86)/<0.001
CFI	0.993	0.997	0.984	0.990
RMSEA	0.067	0.046	0.075	0.064
SRMR	0.026	0.021	0.042	0.039
Loading constrained (Taiwan vs. China)
Δχ² (df)/p-value	153.75 (8)/<0.001	32.55 (5)/<0.001	207.93 (13)/<0.001	182.24 (15)/<0.001
ΔCFI	−0.002	0.000	−0.003	−0.002
ΔRMSEA	0.004	0.001	0.002	0.002
ΔSRMR	0.008	0.003	0.006	0.004
Loadings and intercepts constrained (Taiwan vs. China)
Δχ² (df)/p-value	198.23 (8)/<0.001	500.43 (5)/<0.001	252.63 (10)/<0.001	143.47 (7)/<0.001
ΔCFI	−0.004	−0.030	−0.002	−0.002
ΔRMSEA	0.006	0.037	0.003	0.002
ΔSRMR	0.009	−0.008	0.011	0.043
Configural (male vs. female)
χ² (df)/p-value	466.72(50)/<0.001	201.80 (40)/<0.001	1152.51(98)/<0.001	806.23 (86)/<0.001
CFI	0.994	0.997	0.986	0.991
RMSEA	0.065	0.046	0.074	0.066
SRMR	0.029	0.018	0.047	0.041
Loading constrained (male vs. female)
Δχ² (df)/p-value	55.59 (8)/<0.001	23.07 (5)/<0.001	117.06 (13)/<0.001	109.59 (15)/<0.001
ΔCFI	−0.001	0.000	−0.001	−0.001
ΔRMSEA	−0.001	−0.001	−0.001	−0.002
ΔSRMR	0.007	0.003	0.026	0.027
Loadings and intercepts constrained (male vs. female)
Δχ² (df)/p-value	236.36 (8)/<0.001	186.10 (5)/<0.001	143.41 (10)/<0.001	63.20 (7)/<0.001
ΔCFI	−0.018	−0.010	−0.003	−0.002
ΔRMSEA	0.009	0.016	0.001	0.000
ΔSRMR	−0.023	−0.015	−0.010	−0.021
Configural (health vs. non-health)
χ² (df)/p-value	476.22 (50)/<0.001	186.48 (40)/<0.001	1189.99 (98)/<0.001	803.93 (86)/<0.001
CFI	0.994	0.998	0.985	0.990
RMSEA	0.066	0.043	0.076	0.065
SRMR	0.028	0.020	0.047	0.043
Loading constrained (health vs. non-health)
Δχ² (df)/p-value	60.75 (8)/<0.001	21.24 (5)/<0.001	97.28 (13)/<0.001	116.93 (15)/<0.001
ΔCFI	−0.001	0.000	−0.001	−0.001
ΔRMSEA	−0.001	0.000	−0.002	−0.001
ΔSRMR	0.001	0.001	0.001	0.001
Loadings and intercepts constrained (health vs. non-health)
Δχ² (df)/p-value	105.16 (8)/<0.001	388.86 (5)/<0.001	165.84 (10)/<0.001	72.71 (7)/<0.001
ΔCFI	−0.002	−0.026	−0.003	−0.001
ΔRMSEA	0.002	0.032	0.001	0.001
ΔSRMR	0.003	−0.013	0.005	0.025

CFI = comparative fit index; TLI = Tucker–Lewis index; RMSEA = root mean square error of approximation; SRMR = standardized root mean square residual. Excellent fit values are in bold; i.e., CFI and TLI > 0.95; RMSEA and SRMR < 0.08. Supported measurement invariance values are in bold; i.e., ΔCFI > −0.01; ΔRMSEA < 0.015; ΔSRMR < 0.03 (for factor loading) or < 0.01 (for item intercept). ^a Using correlated trait correlated method minus one model to control wording effects.