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Table 5 A_irt item parameters

From: Measuring the ICF components of impairment, activity limitation and participation restriction: an item analysis using classical test theory and item response theory

  Item parameters
A_irt item Discrim Difficulty: location parameters
  a b1
(se)
b2
(se)
b3
(se)
b4
(se)
A1. What degree of difficulty do you have climbing up and down several flights of stairs? 1.72 -3.73
(0.59)
-2.62
(0.29)
-1.37
(0.14)
0.21
(0.10)
A4. What degree of difficulty do you have bending to floor? 1.91 -2.54
(0.25)
-1.58
(0.16)
-0.32
(0.09)
1.10
(0.12)
A5. What degree of difficulty do you have climbing up and down one flight of stairs?(*) 1.91 -2.76
(0.29)
-1.64
(0.15)
-0.07
(0.09)
1.13
(0.13)
A6. What degree of difficulty do you have putting on socks/stockings? 2.27 -1.87
(0.17)
-1.12
(0.11)
-0.03
(0.07)
0.96
(0.10)
A8. What degree of difficulty do you have rising from sitting? 2.07 -2.82
(0.34)
-1.41
(0.13)
0.34
(0.08)
1.82
(0.17)
A10. What degree of difficulty do you have lifting? 1.79 -2.17
(0.21)
-1.15
(0.12)
0.24
(0.09)
1.70
(0.17)
A11. What degree of difficulty do you have standing? 1.41 -2.90
(0.35)
-1.41
(0.17)
0.41
(0.12)
2.20
(0.26)
A12. What degree of difficulty do you have walking on the flat ? 1.47 -3.27
(0.41)
-1.57
(0.17)
0.52
(0.12)
2.42
(0.29)
A13. What degree of difficulty do you have taking off socks/stockings? 2.34 -1.79
(0.15)
-0.89
(0.10)
0.35
(0.07)
1.14
(0.11)
A14. Do you use a walking stick? 0.95 -1.21
(0.22)
-0.43
(0.17)
-0.20
(0.16)
0.63
(0.18)
A15. What degree of difficulty do you have rising from bed? 3.12 -1.68
(0.13)
-0.80
(0.08)
0.66
(0.07)
1.60
(0.11)
A16. What degree of difficulty do you have putting on/off shoes? 2.29 -1.29
(0.11)
-0.37
(0.09)
0.62
(0.08)
1.51
(0.12)
A17. Does your health now limit you in these activities? Bending, kneeling or stooping 1.02 -4.52
(1.24)
-1.76
(0.34)
  
A18. What degree of difficulty do you have getting on/off toilet? 2.80 -1.36
(0.11)
-0.35
(0.07)
0.95
(0.08)
1.97
(0.16)
A19. What degree of difficulty do you have lying in bed? 2.21 -1.24
(0.11)
-0.30
(0.08)
1.17
(0.11)
2.23
(0.21)
A20. What degree of difficulty do you have sitting? 2.76 -1.19
(0.10)
-0.26
(0.07)
1.29
(0.10)
2.63
(0.27)
A21. What degree of difficulty do you have dressing yourself (except shoes and socks)? 2.71 -0.51
(0.08)
0.27
(0.07)
1.78
(0.13)
2.38
(0.23)
A22. What degree of difficulty do you have washing and drying yourself? 2.53 -0.43
(0.08)
0.24
(0.07)
1.70
(0.14)
2.83
(0.35)
A23. What degree of difficulty do you have washing your hair? 2.05 0.01
(0.08)
0.60
(0.09)
1.86
(0.17)
2.78
(0.32)
A24. Do you need someone to help you go upstairs? 1.63 0.21
(0.10)
1.18
(0.14)
1.64
(0.17)
2.23
(0.24)
A25. Do you need someone to help you when you are walking? 1.33 0.01
(0.11)
1.56
(0.20)
2.20
(0.27)
3.27
(0.44)
A26. Do you need someone to help you go downstairs? 1.59 0.25
(0.10)
1.24
(0.14)
1.66
(0.18)
2.12
(0.23)
TOTAL      
  1. Key: Items in bold = items with low discrimination parameter (< 1.25).