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Table 6 Differential item functioning by modes of administration

From: Score equivalence of paper-, tablet-, and interactive voice response system-based versions of PROMIS, PRO-CTCAE, and numerical rating scales among cancer patients

  McFadden pseudo R2 change (\({R}_{2}^{2}-{R}_{1}^{2}\)) McFadden pseudo R2 change (\({R}_{3}^{2}-{R}_{2}^{2}\)) McFadden pseudo R2 change (\({R}_{3}^{2}-{R}_{1}^{2}\))
Anxiety    
I felt fearful 0.0001 0.0007 0.0005
I found it hard to focus on anything other than my anxiety 0.0041 0.0051 0.0010
My worries overwhelmed me 0.0019 0.0028 0.0008
I felt uneasy 0.0007 0.0015 0.0008
I felt nervous 0.0017 0.0023 0.0006
I felt like I needed help for my anxiety 0.0015 0.0029 0.0014
I felt anxious 0.0002 0.0004 0.0001
I felt tense 0.0011 0.0015 0.0003
(NRS) Describe the level of anxiety on average 0.0005 0.0005 0.0000
(PRO-CTCAE) How often did you feel anxiety? 0.0049 0.0058 0.0009
(PRO-CTCAE) What was the severity of your anxiety at the WORST? 0.0025 0.0025 0.0000
(PRO-CTCAE) How much did anxiety interfere with usual/daily activities? 0.0009 0.0017 0.0008
Depression    
I felt that nothing could cheer me up 0.0144 0.0197 0.0053
I felt worthless 0.0000 0.0007 0.0007
I felt helpless 0.0011 0.0013 0.0001
I felt depressed 0.0055 0.0070 0.0015
I felt hopeless 0.0023 0.0027 0.0004
I felt like a failure 0.0004 0.0009 0.0005
I felt unhappy 0.0041 0.0046 0.0005
I felt that I had nothing to look forward to 0.0031 0.0033 0.0002
(NRS) Describe level of depression on average 0.0018 0.0020 0.0002
(PRO-CTCAE) How often did you feel nothing could cheer you up 0.0014 0.0015 0.0001
(PRO-CTCAE) What was the SEVERITY of feelings that nothing could cheer you up at the WORST? 0.0007 0.0007 0.0000
(PRO-CTCAE) How much did feeling nothing could cheer you up INTERFERE with activities? 0.0002 0.0008 0.0006
(PRO-CTCAE) How OFTEN did you have sad or unhappy feelings 0.0062 0.0066 0.0004
(PRO-CTCAE) What was the SEVERITY of your sad/unhappy feelings at the WORST? 0.0044 0.0047 0.0003
(PRO-CTCAE) How much did sad/unhappy feelings INTERFERE with activities? 0.0003 0.0003 0.0001
Fatigue    
How often did you feel tired? 0.0005 0.0007 0.0002
How often did you experience extreme exhaustion? 0.0002 0.0002 0.0000
How often did you run out of energy? 0.0014 0.0017 0.0003
How often did your fatigue limit you at work? 0.0001 0.0004 0.0003
How often were you too tired to think clearly? 0.0000 0.0004 0.0004
How often were you too tired to take a bath or shower? 0.0006 0.0012 0.0007
How often did you have enough energy to exercise strenuously? 0.0005 0.0013 0.0007
How often did you have to push yourself to get things done because of your fatigue? 0.0023 0.0029 0.0006
How often did you have trouble finishing things because of your fatigue? 0.0002 0.0005 0.0003
(NRS) Describe level of fatigue 0.0003 0.0010 0.0007
(PRO-CTCAE) What was severity of fatigue at its worst? 0.0000 0.0002 0.0001
(PRO-CTCAE) How much did fatigue interfere with activities? 0.0000 0.0005 0.0002
Pain interference    
How much did pain interfere with your family life? 0.0001 0.0002 0.0001
How much did pain interfere with work around the home? 0.0010 0.0021 0.0011
How much did pain interfere with your ability to participate in social activities? 0.0026 0.0029 0.0003
How much did pain interfere with your enjoyment of life? 0.0002 0.0004 0.0003
How much did pain interfere with the things you usually do for fun? 0.0007 0.0009 0.0002
How much did pain interfere with your enjoyment of social activities? 0.0002 0.0007 0.0005
How much did pain interfere with your household chores? 0.0003 0.0009 0.0006
(PRO-CTCAE) How much did pain interfere with activities? 0.0009 0.0019 0.0010
Pain intensity    
How intense was pain at its worst? 0.0016 0.0026 0.0010
How intense was your average pain? 0.0014 0.0018 0.0004
What is your level of pain right now? 0.0001 0.0002 0.0002
(NRS) Rate severity of pain 0.0000 0.0003 0.0003
(PRO-CTCAE) What was severity of pain at its worst? 0.0005 0.0015 0.0010
Physical function    
Does your health now limit you in doing vigorous activities such as running, lifting heavy objects, participating in strenuous sports? 0.0013 0.0018 0.0005
Are you able to get on and off the toilet? 0.0000 0.0014 0.0014
Does your health now limit you in walking more than a mile? 0.0010 0.0012 0.0002
Does your health now limit you in climbing one flight of stairs? 0.0003 0.0003 0.0000
Does your health now limit you in lifting or carrying groceries? 0.0011 0.0012 0.0001
Does your health now limit you in bending, kneeling, or stooping? 0.0009 0.0015 0.0006
Are you able to do chores such as vacuuming or yard work? 0.0020 0.0042 0.0022
Are you able to dress yourself, including tying shoelaces and doing buttons? 0.0018 0.0021 0.0003
Are you able to shampoo your hair? 0.0053 0.0061 0.0008
Are you able to wash and dry your body? 0.0021 0.0043 0.0022
(NRS) Overall physical well-being 0.0003 0.0006 0.0004
Sleep disturbance    
My sleep quality was 0.0013 0.0023 0.0010
My sleep was refreshing 0.0002 0.0005 0.0002
I had a problem with my sleep 0.0007 0.0011 0.0004
I had difficulty falling asleep 0.0013 0.0021 0.0008
My sleep was restless 0.0007 0.0012 0.0006
I tried hard to get to sleep 0.0002 0.0006 0.0004
I worried about not being able to fall asleep 0.0003 0.0005 0.0001
I was satisfied with my sleep 0.0001 0.0001 0.0000
(NRS) Describe quality of sleep on average 0.0002 0.0006 0.0004
(PRO-CTCAE) What was the severity of your insomnia at its worst? 0.0039 0.0045 0.0007
(PRO-CTCAE) How much has insomnia interfered with usual activities? 0.0045 0.0051 0.0006
Ability to participate in social roles and activities    
I have trouble doing all of my regular leisure activities with others 0.0010 0.0021 0.0011
I have trouble doing all of the family activities that I want to do 0.0005 0.0010 0.0005
I have trouble doing all of my usual work (include work at home) 0.0001 0.0009 0.0009
I have trouble doing all of the activities with friends that I want to do 0.0001 0.0006 0.0004
I have to limit the things I do for fun with others 0.0002 0.0008 0.0006
I have to limit my regular activities with friends 0.0002 0.0004 0.0001
I have to limit my regular family activities 0.0008 0.0009 0.0001
I have trouble doing all of the work that is really important to me (include work at home) 0.0013 0.0016 0.0003
(NRS) Rate level of social activity 0.0007 0.0008 0.0001
Global mental health    
In general, would you say your quality of life is…? 0.0008 0.0025 0.0017
In general, how would you rate your mental health, including your mood and your ability to think? 0.0074 0.0094 0.0019
In general, how would you rate your satisfaction with your social activities and relationships? 0.0002 0.0012 0.0010
How would you rate your fatigue on average? 0.0067 0.0069 0.0002
(NRS) Rate your overall QOL 0.0003 0.0005 0.0002
(NRS) Rate your emotional well-being 0.0008 0.0023 0.0015
(NRS) Rate your mental well-being 0.0035 0.0046 0.0011
Global physical health    
In general, how would you rate your physical health? 0.0045 0.0049 0.0004
To what extent are you able to carry out everyday physical activities such as walking, climbing stairs, carrying groceries, or moving a chair? 0.0041 0.0043 0.0001
Rate fatigue on average 0.0039 0.0041 0.0003
(NRS) Rate pain on average 0.0000 0.0001 0.0000
(ECOG) Best description of current activity level 0.0026 0.0027 0.0001
  1. A base model (model 1) posits that only the trait level predicts responses. A second model (model 2) has both trait level and group as independent variables. If model 2 predicts item responses statistically significantly better than model 1 (i.e., McFadden pseudo R2 change (\({R}_{2}^{2}-{R}_{1}^{2}\)) ≥ 0.02), then there is uniform DIF. In uniform DIF, DIF has a consistent impact across trait levels. If the model that includes an interaction term between trait and group (model 3) fits significantly better than model 2 (i.e., McFadden pseudo R2 change (\({R}_{3}^{2}-{R}_{2}^{2}\)) ≥ 0.02), then the impact of DIF varies by trait level (nonuniform DIF). If model 3 fits significantly better than model 1 (i.e., McFadden pseudo R2 change (\({R}_{3}^{2}-{R}_{1}^{2}\)) ≥ 0.02), there is overall or total DIF