Table 4.
Differential item functioning positive and negative symptoms: reference group = USA vs. focal group = Northern European, Southern Europe and Russia & Ukraine
| Northern Europe | Southern Europe | Russia & Ukraine | USA | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Item | Chi-sq | p-value | E.S. (95% C.I.) | Class | Northern Europe Mean | Chi-sq | p-value | E.S. (95% C.I.) | Class | Southern Europe Mean | Chi-sq | p-value | E.S. (95% C.I.) | Class | Russo Europe | USA Mean |
| P1 | 0.79 | 0.38 | −0.02 (−0.21;0.17) | A | 4.60 (1.06) | 27.73 | < 0.001 | −0.56 (−0.76;-0.35) | B- | 3.66 (0.75)* | 6.06 | 0.01 | −0.31 (−0.50;-0.12) | BB- | 3.86 (0.84) | 4.29 (1.05) |
| P2 | 4.16 | 0.04 | 0.22 (−0.04;0.48) | A | 3.97 (0.99) | 26.9 | < 0.001 | 0.83 (0.56;1.10) | C+ | 4.05 (1.34)* | 6.58 | 0.01 | 0.34 (0.12;0.55) | BB+ | 3.56 (0.77) | 3.42 (1.34) |
| P3 | 3.93 | 0.05 | 0.12 (−0.03;0.27) | A | 4.79 (0.68) | 4.48 | 0.03 | 0.20 (0.03;0.38) | A | 4.24 (0.82) | 8.68 | < 0.001 | 0.24 (0.09;0.38) | AA | 4.40 (0.84)* | 4.33 (0.96) |
| P4 | 0.84 | 0.36 | −0.07 (−0.26;0.12) | A | 3.11 (1.13) | 2.55 | 0.11 | −0.18 (−0.35;-0.01) | A | 2.07 (1.25) | 0.42 | 0.52 | −0.04 (−0.21;0.12) | AA | 2.40 (1.24) | 2.70 (1.80) |
| P5 | 0.4 | 0.53 | 0.12 (−0.06;0.31) | A | 3.98 (1.43) | 40.17 | < 0.001 | −0.63 (−0.83;-0.42) | C- | 2.10 (1.49)* | 2.2 | 0.14 | −0.04 (−0.23;0.15) | AA | 2.87 (1.40) | 3.34 (1.33) |
| P6 | 15.42 | < 0.001 | −0.33 (−0.51;-0.15) | B- | 4.46 (0.88)* | 12.95 | < 0.001 | −0.39 (−0.59;-0.20) | B- | 1.09 (0.81)* | 27.12 | < 0.001 | −0.59 (−0.80;-0.39) | BB- | 3.88 (1.20)* | 4.64 (1.02) |
| P7 | 0.3 | 0.59 | −0.04 (−0.25;0.18) | A | 3.39 (0.93) | 56.93 | < 0.001 | 0.72 (0.53;0.91) | C+ | 3.32 (1.03)* | 14.33 | < 0.001 | 0.41 (0.22;0.60) | BB+ | 3.21 (1.13)* | 3.05 (1.26) |
| N1 | 34.81 | <0.001 | −0.56 (−0.76;-0.36) | BB- | 3.91 (1.30)* | 1.89 | 0.17 | −0.09 (−0.24;0.05) | AA | 4.46 (1.29) | 0.4 | 0.53 | −0.03 (−0.26;0.19) | AA | 4.10 (1.09) | 4.01 (1.67) |
| N2 | 0.6 | 0.44 | 0.07 (−0.05;0.20) | AA | 3.94 (0.55) | 0.46 | 0.5 | 0.03 (−0.07;0.12) | AA | 4.02 (0.61) | 0.48 | 0.49 | −0.08 (−0.22;0.06) | AA | 3.63 (0.76) | 3.85 (0.79) |
| N3 | 1 | 0.32 | 0.10 (−0.08;0.27) | AA | 3.56 (1.30) | 30.61 | < 0.001 | 0.44 (0.29;0.59) | BB+ | 4.04 (1.23)* | 7.54 | 0.01 | 0.20 (0.05;0.34) | AA | 3.24 (0.85) | 3.26 (1.51) |
| N4 | 0.01 | 0.93 | 0.01 (−0.16;0.17) | AA | 3.84 (0.99) | 37.25 | < 0.001 | −0.55 (−0.70;-0.39) | BB- | 3.49 (0.84)* | 2.27 | 0.13 | 0.02 (−0.15;0.19) | AA | 3.52 (0.87) | 3.74 (1.23) |
| N5 | 0.03 | 0.86 | −0.03 (−0.23;0.18) | AA | 4.41 (1.14) | 15.71 | < 0.001 | −0.36 (−0.55;-0.18) | BB- | 4.04 (1.07)* | 7.78 | 0.01 | −0.24 (−0.44;-0.04) | AA | 3.94 (0.94) | 4.16 (1.32) |
| N6 | 0.93 | 0.33 | 0.06 (−0.12;0.24) | AA | 3.99 (1.39) | 20.58 | < 0.001 | 0.36 (0.20;0.51) | BB+ | 4.39 (1.30)* | 9.07 | < 0.001 | 0.02 (−0.17;0.21) | AA | 3.54 (1.08)* | 3.52 (1.73) |
| N7 | 10.44 | <0.001 | 0.35 (0.15;0.56) | BB+ | 3.25 (0.86)* | 2.44 | 0.12 | 0.18 (−0.00;0.37) | AA | 3.21 (0.99) | 0.33 | 0.57 | 0.11 (−0.06;0.29) | AA | 2.89 (0.77) | 2.17 (1.15) |
* Bonferroni Corrected p <0 .0017; E.S.: Effect Size; Chi-sq: Chi Square.