Table 3 Item fit statistics and differential item functioning (DIF) for age and gender
CTS-6 | Location | Fit residual | DF | Chi-square | P | DIF Gender (U/NON-U) | DIF Age (U/NON-U) |
Item | |||||||
How severe are the following symptoms in your hand? | |||||||
1. Pain at night | 0,068 | -1,212 | 123,67 | 4,006 | 0,26 | - | - |
2. Pain during daytime | 1,209 | 1,671 | 123,67 | 1,773 | 0,62 | - | - |
3. Numbness or tingling at night | -0,752 | -0,524 | 123,67 | 1,749 | 0,62 | - | P=0.0498 |
4. Numbness or tingling during daytime | -0,441 | 0,520 | 123,67 | 3,048 | 0,38 | - | - |
How often did the following symptoms in your hand wake you up at night? | |||||||
5. Pain | 0,239 | -0,220 | 123,67 | 1,381 | 0,71 | - | - |
6. Numbness or tingling | -0,323 | -1,057 | 123,67 | 3,249 | 0,36 | (P=0.0008) | - |
BCTQ Symptom Severity Scale | Location | Fit residual | DF | Chi-square | P | DIF Gender (U/NON-U) | DIF Age (U/NON-U) |
Item | |||||||
1. How severe is the hand or wrist pain that you have at night? | 0,598 | -0,879 | 167,00 | 1,893 | 0,60 | - | - |
2. How often did hand or wrist pain wake you up during a typical night in the past two weeks? | 2,133 | 1,745 | 167,00 | 3,011 | 0,39 | - | - |
3. Do you typically have pain in your hand or wrist during the daytime? | 0,373 | -2,112 | 167,00 | 7,312 | 0,06 | - | - |
4. How often do you have hand or wrist pain during daytime? | -0,78 | -0,929 | 167,00 | 6,736 | 0,08 | - | - |
5. How long on average does an episode of pain last during the daytime? | -1,112 | -0,232 | 167,00 | 9,340 | 0,03 | - | NON-U; P=0.020 |
6. Do you have numbness (loss of sensation) in your hand? | -0,290 | 1,089 | 167,00 | 9,340 | 0,13 | - | - |
7. Do you have weakness in your hand or wrist? | -0,915 | 1,507 | 167,00 | 7,979 | 0,05 | U; P=0.003 | - |
8. Do you have tingling sensations in your hand? | -0,141 | -0,648 | 167,00 | 1,421 | 0,70 | - | - |
9. How severe is numbness (loss of sensation) or tingling at night? | -0,007 | -1,604 | 167,00 | 4,850 | 0,18 | - | - |
10. How often did hand numbness or tingling wake you up during a typical night during the past two weeks? | 0,510 | -0,917 | 167,00 | 3,590 | 0,31 | - | - |
11. Do you have difficulty with the grasping and use of small objects such as keys or pens? | -0,369 | 1,818 | 167,00 | 6,739 | 0,08 | - | - |
BCTQ Functional Status Scale | Location | Fit residual | DF | Chi-square | P | DIF Gender (U/NON-U) | DIF Age (U/NON-U) |
Item | |||||||
1. Writing | 1,454 | 0,140 | 137,88 | 6,934 | 0,07 | - | |
2. Buttoning of clothes | -0,591 | -0,188 | 137,88 | 2,659 | 0,45 | U; P=0.020 | U; P<0.001 |
3. Holding a book while reading | -0,997 | 0,985 | 137,88 | 2,626 | 0,45 | - | - |
4. Gripping of a telephone handle | 1,462 | -0,542 | 137,88 | 3,175 | 0,37 | NON-U; P=0.0007 | U; P=0.0002 |
5. Opening of jars | -1,623 | 1,471 | 137,88 | 3,585 | 0,31 | - | U; P<0.001 |
6. Household chores | -0,477 | -1,555 | 137,88 | 6,488 | 0,09 | NON-U; P=0.020 | - |
7. Carrying of grocery bags | -0,887 | -0,094 | 137,88 | 2,540 | 0,47 | - | U; P=0.004 |
8. Bathing and dressing | 1,659 | -1,660 | 137,88 | 6,785 | 0,08 | - | U; P=0.020 |