Table 3.
Measures of goodness-of-fit of models testing Generalized Anxiety Disorder 7-item scale (GAD-7) measurement invariance by gender and age in adults (N = 821) employed in 4 economic sectors (health care, education, IT, public administration) during the initial phase of the COVID-19 pandemic, April 10–May 24, 2020, Poland
| Level of measurement equivalence | Modified univariate model (model 2) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| χ2 (df) | CFI | TLI | RMSEA (90% CI) | SRMR | Δχ2 (df) | ΔCFI | ΔRMSEA | ΔSRMR | |
| Age | |||||||||
| construct | 54.74 (20) | 0.99 | 0.99 | 0.05 (0.03–0.06) | 0.01 | – | – | – | – |
| metric | 62.15 (26) | 0.99 | 0.99 | 0.04 (0.03–0.05) | 0.01 | 7.41 (6) | −0.001 | −0.005 | 0.001 |
| scalar | 74.90 (33) | 0.99 | 0.99 | 0.04 (0.03–0.05) | 0.01 | 12.75 (7) | –0.001 | –0.002 | <0.001 |
| Gender | |||||||||
| construct | 73.0 (14) | 0.99 | 0.98 | 0.06 (0.04–0.07) | 0.01 | – | – | – | – |
| metric | 79.63 (27) | 0.99 | 0.99 | 0.05 (0.04–0.06) | 0.01 | 6.63 (13) | <0.001 | −0.008 | <0.001 |
| scalar | 94.42 (32) | 0.99 | 0.99 | 0.05 (0.04–0.06) | 0.02 | 14.79 (5) | −0.001 | <0.001 | 0.002 |
CFI – comparative fit index; df – degrees of freedom; RMSEA – root mean square error of approximation; SRMR – standardized root mean squared residual; TLI – Tucker-Lewis index.