Table 2. IRT item characteristics for the Dutch-Flemish PROMIS Pain Interference item bank.
| Category threshold | Item fit statistics | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Item code | Item | Slope a | B1 | B2 | B3 | B4 | Mokken’s H | S-X2 | Prob X2 |
| PAININ1 | How difficult was it for you to take in new information because of pain? | 1.69 | -1.63 | -0.47 | 0.61 | 1.91 | 0.62 | 40.00 | 0.470 |
| PAININ3 | How much did pain interfere with your enjoyment of life? ◊ | 2.35 | -2.11 | -0.89 | 0.07 | 1.42 | 0.67 | 41.55 | 0.403 |
| PAININ5 | How much did pain interfere with your ability to participate in leisure activities? | 2.55 | -2.25 | -1.11 | -0.17 | 1.12 | 0.69 | 56.74 | 0.042 |
| PAININ6 | How much did pain interfere with your close personal relationships? | 2.43 | -1.39 | -0.45 | 0.47 | 1.80 | 0.67 | 39.66 | 0.486 |
| PAININ8 | How much did pain interfere with your ability to concentrate? | 1.67 | -2.06 | -0.89 | 0.22 | 1.67 | 0.61 | 25.67 | 0.962 |
| PAININ9 | How much did pain interfere with your day to day activities? * ◊ | 2.01 | -2.94 | -1.45 | -0.27 | 1.45 | 0.66 | 29.87 | 0.879 |
| PAININ10 | How much did pain interfere with your enjoyment of recreational activities? | 2.63 | -2.15 | -0.96 | -0.13 | 1.21 | 0.69 | 34.88 | 0.670 |
| PAININ11 | How often did you feel emotionally tense because of your pain? | 1.91 | -2.07 | -0.99 | 0.06 | 1.35 | 0.65 | 38.22 | 0.550 |
| PAININ12 | How much did pain interfere with the things you usually do for fun? ◊ | 2.56 | -2.24 | -1.00 | -0.12 | 1.25 | 0.69 | 39.27 | 0.503 |
| PAININ13 | How much did pain interfere with your family life? ◊ | 2.22 | -1.68 | -0.72 | 0.26 | 1.71 | 0.66 | 75.62 | 0.0006# |
| PAININ14 | How much did pain interfere with doing your tasks away from home (e.g., getting groceries, running errands)? | 2.21 | -1.65 | -0.70 | 0.13 | 1.40 | 0.67 | 58.31 | 0.031 |
| PAININ16 | How often did pain make you feel depressed? | 1.55 | -1.61 | -0.62 | 0.78 | 2.54 | 0.60 | 35.61 | 0.668 |
| PAININ17 | How much did pain interfere with your relationships with other people? | 2.39 | -1.54 | -0.50 | 0.46 | 1.84 | 0.67 | 38.69 | 0.529 |
| PAININ18 | How much did pain interfere with your ability to work (include work at home)? | 2.29 | -2.41 | -1.30 | -0.50 | 0.78 | 0.68 | 50.47 | 0.124 |
| PAININ19 | How much did pain make it difficult to fall asleep? | 1.40 | -2.00 | -0.91 | 0.10 | 1.27 | 0.58 | 45.68 | 0.248 |
| PAININ20 | How much did pain feel like a burden to you? | 2.23 | -3.04 | -1.57 | -0.56 | 0.83 | 0.68 | 31.83 | 0.818 |
| PAININ22 | How much did pain interfere with work around the home? * ◊ | 2.21 | -2.57 | -1.43 | -0.48 | 1.04 | 0.67 | 30.76 | 0.853 |
| PAININ24 | How often was pain distressing to you? ^ | 1.48 | -2.11 | -0.99 | 0.46 | 2.31 | 0.59 | 49.22 | 0.150 |
| PAININ26 | How often did pain keep you from socializing with others? | 2.25 | -2.00 | -1.10 | 0.17 | 2.10 | 0.68 | 46.81 | 0.213 |
| PAININ29 | How often was your pain so severe you could think of nothing else? | 1.83 | -1.66 | -0.57 | 0.73 | 2.55 | 0.64 | 29.25 | 0.895 |
| PAININ31 | How much did pain interfere with your ability to participate in social activities? * ◊ | 3.02 | -1.92 | -0.83 | 0.01 | 1.41 | 0.70 | 38.61 | 0.533 |
| PAININ32 | How often did pain make you feel discouraged? ^ | 1.77 | -2.05 | -1.04 | 0.38 | 2.37 | 0.63 | 53.84 | 0.071 |
| PAININ34 | How much did pain interfere with your household chores? * ◊ | 2.13 | -2.63 | -1.44 | -0.46 | 1.06 | 0.67 | 24.70 | 0.973 |
| PAININ35 | How much did pain interfere with your ability to make trips from home that kept you gone for more than 2 hours? | 2.47 | -1.37 | -0.65 | 0.12 | 1.23 | 0.68 | 59.18 | 0.026 |
| PAININ36 | How much did pain interfere with your enjoyment of social activities? ◊ | 2.66 | -1.92 | -0.90 | -0.08 | 1.26 | 0.69 | 35.55 | 0.671 |
| PAININ37 | How often did pain make you feel anxious? | 1.37 | -1.75 | -0.66 | 0.84 | 2.58 | 0.56 | 47.58 | 0.191 |
| PAININ38 | How often did you avoid social activities because it might make you hurt more? | 1.92 | -1.67 | -0.83 | 0.26 | 1.95 | 0.64 | 49.50 | 0.144 |
| PAININ40 | How often did pain prevent you from walking more than 1 mile? | 1.28 | -2.12 | -1.23 | -0.24 | 1.03 | 0.54 | 58.90 | 0.027 |
| PAININ42 | How often did pain prevent you from standing for more than one hour? | 1.20 | -2.63 | -1.77 | -0.82 | 0.63 | 0.54 | 73.47 | 0.001# |
| PAININ46 | How often did pain make it difficult for you to plan social activities? | 2.31 | -1.93 | -1.04 | 0.04 | 1.58 | 0.69 | 38.31 | 0.546 |
| PAININ47 | How often did pain prevent you from standing for more than 30 minutes? | 1.21 | -2.26 | -1.39 | -0.17 | 1.20 | 0.54 | 63.38 | 0.011 |
| PAININ48 | How much did pain interfere with your ability to do household chores? | 2.20 | -2.38 | -1.19 | -0.33 | 1.09 | 0.68 | 30.49 | 0.861 |
| PAININ49 | How much did pain interfere with your ability to remember things? | 1.48 | -1.51 | -0.31 | 0.71 | 2.05 | 0.59 | 38.31 | 0.547 |
| PAININ50 | How often did pain prevent you from sitting for more than 30 minutes? | 1.42 | -1.53 | -0.50 | 0.62 | 2.00 | 0.58 | 44.04 | 0.304 |
| PAININ51 | How often did pain prevent you from sitting for more than 10 minutes? | 1.28 | -0.73 | 0.44 | 1.82 | 3.44 | 0.56 | 34.79 | 0.703 |
| PAININ52 | How often was it hard to plan social activities because you didn't know if you would be in pain? | 1.82 | -1.50 | -0.70 | 0.24 | 1.73 | 0.64 | 30.34 | 0.865 |
| PAININ53 | How often did pain restrict your social life to your home? | 2.17 | -1.61 | -0.79 | 0.26 | 1.93 | 0.68 | 36.70 | 0.620 |
| PAININ54 | How often did pain keep you from getting into a standing position? | 0.95 | -0.86 | -0.01 | 0.91 | 1.76 | 0.48 | 50.43 | 0.125 |
| PAININ55 | How often did pain prevent you from sitting for more than one hour? | 1.32 | -1.65 | -0.77 | 0.21 | 1.77 | 0.56 | 45.82 | 0.243 |
| PAININ56 | How irritable did you feel because of pain? | 1.67 | -2.29 | -0.72 | 0.41 | 1.78 | 0.61 | 40.50 | 0.448 |
^ uniform DIF due to language (Dutch versus English). Activity is relatively faster endorsed in US chronic pain patients.
* item included in the 4-item short form (V1.0.4a).
◊ item included in the 8-item short form (V1.0.8a).
# p≤0.001.