Table 2 Goodness of fit for Confirmatory factor analysis of PHQ-9, GAD-7 and WSAS (n = 831)

 1. PHQ-9 single factor

341.080^***

27

.118 [.107–.130]

.937

.916

 2. PHQ-9 two-factor

105.070^***

26

.060 [.049–.073]

.984

.978

 3. PHQ-9 bifactor-(Sc – 1)

101.667^***

23

.064 [.052–.077]

.984

.975

 4. PHQ-9 bifactor-(Ss – 1)

103.436^***

22

.067 [.054–.080]

.984

.973

 5. GAD-7 single factor

183.117^***

14

.121 [.105–.136]

.976

.964

 6. GAD-7 single factor mod.¹

50.288^***

11

.066 [.048–.084]

.994

.989

 7. GAD-7 two-factor

61.920^***

13

.067 [.051–.085]

.993

.989

 8. GAD-7 two-factor mod.²

45.815^***

12

.058 [.041–.077]

.995

.991

 9. GAD-7 bifactor-(Sc – 1)

42.805^***

10

.063 [.044–.083]

.995

.990

 10. GAD-7 bifactor-(Ss – 1)

50.288^***

11

.066 [.048–.084]

.994

.989

 11. WSAS single factor

138.321^***

5

.179 [.154–.205]

.953

.906

 12. WSAS mod.³

14.235^***

4

.055 [.026–.088]

.996

.991

 13. WSAS mod.³ & PHQ-9 bifactor-(Sc – 1)

274.640^***

70

.059 [.052–.067]

.976

.968

 14. WSAS mod.³ & PHQ-9 bifactor-(Ss – 1)

274.386^***

69

.060 [.053–.067]

.975

.968

 15. WSAS mod.³ & GAD-7 bifactor-(Sc – 1)

180.710^***

47

.059 [.050–.068]

.985

.979

 16. WSAS mod.³ & GAD-7 bifactor-(Ss – 1)

195.707^***

48

.061 [.052–.070]

.983

.977