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Table 6 Item discrimination, difficulty, and average amount of information in item response theory

From: Comparing the reliability and validity of the SF-36 and SF-12 in measuring quality of life among adolescents in China: a large sample cross-sectional study

Label SF-36 SF-12
Item discrimination (SD) Item difficulty (SD) Average amount of information Item discrimination (SD) Item difficulty (SD) Average amount of information
Physical functioning (PF)
PF01 2.73 (0.01)  − 1.43 (0.01) 1.02    
0.21 (0.01)
PF02 2.73 (0.01)  − 2.53 (0.05) 0.74 2.20 (0.03)  − 3.13 (0.05) 0.45
 − 1.07 (0.01)  − 1.40 (0.02)
PF03 2.73 (0.01)  − 2.55 (0.05) 0.73    
 − 1.14 (0.01)
PF04 2.73 (0.01)  − 2.05 (0.03) 0.9 2.20 (0.03)  − 2.60 (0.04) 0.54
 − 0.87 (0.01)  − 1.17 (0.01)
PF05 2.73 (0.01)  − 2.45 (0.04) 0.65    
 − 1.54 (0.02)
PF06 2.73 (0.01)  − 1.88 (0.02) 0.89    
 − 0.90 (0.01)
PF07 2.73 (0.01)  − 1.42 (0.01) 0.95    
 − 0.25 (0.01)
PF08 2.73 (0.01)  − 1.96 (0.03) 0.89    
 − 0.92 (0.01)
PF09 2.73 (0.01)  − 2.51 (0.05) 0.63    
 − 1.58 (0.02)
PF10 2.73 (0.01)  − 1.69 (0.02) 0.74    
 − 1.20 (0.01)
Role physical (RP)
RP1 2.17 (0.02) 0.77 (0.01) 0.43    
RP2 2.17 (0.02) 0.53 (0.01) 0.43 2.32 (0.03) 0.52 (0.01) 0.46
RP3 2.17 (0.02) 0.65 (0.01) 0.43 2.32 (0.03) 0.63 (0.01) 0.46
RP4 2.17 (0.02) 0.52 (0.01) 0.43    
Bodily pain (BP)
BP1 0.45 (0.01)  − 10.26 (0.48) 0.06    
 − 8.08 (0.31)
 − 4.60 (0.16)
 − 1.33 (0.06)
1.24 (0.06)
BP2 0.45 (0.01) 0.32 (0.05) 0.05 1.06 (0.02) 0.18 (0.02) 0.24
4.65 (0.17) 2.40 (0.04)
7.46 (0.28) 3.83 (0.07)
10.00 (0.44) 5.28 (0.12)
General health (GH)
GH1 1.76 (0.01)  − 3.05 (0.05) 0.76 0.91 (0.01)  − 1.80 (0.03) 0.24
 − 1.11 (0.02) 0.21 (0.02)
 − 0.13 (0.01) 1.72 (0.03)
1.2 (0.01) 4.93 (0.09)
GH2 1.76 (0.01)  − 2.33 (0.03) 0.73    
 − 1.46 (0.02)
 − 0.23 (0.01)
0.54 (0.01)
GH3 1.76 (0.01)  − 2.77 (0.03) 0.68    
 − 2.14 (0.02)
 − 0.89 (0.01)
0.35 (0.01)
GH4 1.76 (0.01)  − 2.43 (0.03) 0.67    
 − 1.55 (0.02)
 − 0.52 (0.01)
0.17 (0.01)
GH5 1.76 (0.01)  − 2.75 (0.03) 0.71    
 − 2.04 (0.02)
 − 0.78 (0.01)
0.57 (0.01)
Vitality (VT)
VT1 0.74 (0.00)  − 2.43 (0.04) 0.17    
0.29 (0.03)
1.68 (0.03)
3.33 (0.05)
4.71 (0.07)
VT2 0.74 (0.00)  − 2.74 (0.04) 0.17 0.91 (0.01)  − 2.36 (0.01) 0.25
 − 0.40 (0.03)  − 0.35 (0.02)
1.22 (0.03) 1.07 (0.02)
2.89 (0.04) 2.50 (0.04)
  3.90 (0.07)
VT3 0.74 (0.00)  − 4.73 (0.07) 0.16    
 − 3.10 (0.04)
 − 1.97 (0.03)
 − 0.50 (0.03)
2.10 (0.03)
VT4 0.74 (0.00)  − 4.26 (0.06) 0.18    
 − 2.55 (0.04)
 − 1.36 (0.03)
0.15 (0.03)
2.93 (0.04)
Social functioning (SF)
SF1 0.50 (0.01)  − 1.68 (0.06) 0.07    
2.80 (0.08)
5.92 (0.17)
8.66 (0.29)
SF2 0.50 (0.01)  − 6.35 (0.18) 0.07 1.07 (0.02)  − 3.42 (0.06) 0.28
 − 4.73 (0.13)  − 2.58 (0.04)
 − 3.48 (0.10)  − 1.92 (0.03)
 − 2.06 (0.07)  − 1.15 (0.02)
 − 0.01 (0.05)  − 0.02 (0.02)
Role emotional (RE)
RE1 1.82 (0.02) 0.35 (0.01) 0.36    
RE2 1.82 (0.02) 0.23 (0.01) 0.36 1.63 (0.02) 0.24 (0.01) 0.31
RE3 1.82 (0.02)  − 0.07 (0.01) 0.36 1.63 (0.02)  − 0.07 (0.01) 0.32
Mental health (MH)
MH1 0.78 (0.00)  − 4.35 (0.07) 0.19    
 − 2.59 (0.04)
 − 1.53 (0.03)
 − 0.33 (0.03)
1.50 (0.03)
MH2 0.78 (0.00)  − 4.49 (0.07) 0.18    
 − 2.99 (0.04)
 − 2.12 (0.03)
 − 1.01 (0.03)
0.82 (0.03)
MH3 0.78 (0.00)  − 11 (–) 0.19 0.79 (0.01)  − 3.94 (0.06) 0.2
 − 2.84 (0.07)  − 2.24 (0.03)
 − 0.42 (0.03)  − 0.82 (0.03)
1.03 (0.03) 0.55 (0.03)
2.72 (0.04) 2.91 (0.04)
MH4 0.78 (0.00)  − 4.83 (0.08) 0.18 0.79 (0.01)  − 4.73 (0.07) 0.18
 − 3.18 (0.05)  − 3.18 (0.04)
 − 2.15 (0.03)  − 2.19 (0.03)
 − 0.82 (0.03)  − 0.88 (0.03)
2.04 (0.03) 2.00 (0.03)
MH5 0.78 (0.00)  − 11.18 (–) 0.18    
 − 1.35 (0.04)
0.84 (0.03)
2.05 (0.03)
3.48 (0.05)
HT 0.91 (0.00)  − 4.84 (0.09) 0.23    
 − 2.59 (0.04)
 − 0.23 (0.02)
1.25 (0.03)
  1. SD standard deviation