Table 4 Measurement invariance using bifactor-(Sc – 1) solution of PHQ-9 and GAD-7

 Configural

120.690 (46)

.985

.063 [.049–.076]

–

–

–

–

 Metric

117.193 (57)

.988

.050 [.037–.063]

8.210 (11)

.694

.003

−.013

 Scalar

130.459 (73)

.989

.044 [.031–.055]

18.611 (16)

.289

.001

−.006

 Configural

59.039 (20)

.994

.069 [.049–.089]

–

–

–

–

 Metric

70.058 (29)

.994

.058 [.041–.076]

17.209 (9)

.046

.000

−.011

 Scalar

68.998 (41)

.996

.041 [.023–.057]

4.492 (12)

.973

.002

−.017

 Configural

108.401 (46)

.969

.083 [.063–.103]

–

–

–

–

 Metric

128.598 (57)

.980

.063 [.048–.077]

26.805 (11)

.005

.011

−.020

 Scalar

144.209 (73)

.980

.055 [.042–.069]

20.402 (16)

.203

.000

−.008

 Configural

26.786 (20)

.998

.041 [.000–.079]

–

–

–

–

 Metric

38.262 (29)

.997

.040 [.000–.072]

12.163 (9)

.204

−.001

−.001

 Scalar

58.513 (41)

.994

.047 [.012–.072]

20.473 (12)

.059

−.003

.007

 Configural

105.079 (46)

.984

.063 [.047–.080]

–

–

–

–

 Metric

128.598 (57)

.980

.063 [.048–.077]

26.805 (11)

.005

−.004

.000

 Scalar

144.209 (73)

.980

.055 [.042–.069]

20.402 (16)

.203

.000

−.008

 Configural

44.238 (20)

.996

.062 [.037–.086]

–

–

–

–

 Metric

47.574 (29)

.997

.045 [.019–.067]

8.708 (9)

.465

.001

−.017

 Scalar

59.560 (41)

.997

.038 [.012–.057]

13.513 (12)

.333

.000

−.007