Background
Conception of research questions
Objectives
Methods
Research data resource
Data analysis using the Rasch model
Excel module for data simulation
Difficulty | Measure | Observed | Expected | ||
---|---|---|---|---|---|
No. |
Items
|
Logit*
|
SE
|
IN.MSQ
|
IN.MSQ
|
5 | Do you need help with eating, dressing, washing yourself or using the toilet? | 2.4 | 0.31 |
1.60
| 1.21 |
3 | Do you have any trouble taking a short walk outside of the house? | 1.45 | 0.23 | 1.04 | 0.85 |
15 | Have you vomited? | 1.15 | 0.21 | 1.61 | 1.2 |
17 | Have you had diarrhea? | 0.97 | 0.21 | 1.17 | 0.93 |
8 | Were you short of breath? | 0.73 | 0.2 | 1.2 | 0.91 |
6 | Were you limited in doing either your work or other daily activities? | 0.69 | 0.19 | 0.95 | 1.03 |
16 | Have you been constipated? | 0.66 | 0.19 | 1.19 | 0.87 |
14 | Have you felt nauseated? | 0.58 | 0.19 | 1.41 | 1.09 |
7 | Were you limited in pursuing your hobbies or other leisure time activities? | 0.31 | 0.18 | 1.05 | 0.77 |
19 | Did pain interfere with your daily activities? | 0.28 | 0.18 | 1.05 | 0.91 |
20 | Difficulty in concentrating on things, like reading papers or watching TV? | 0.25 | 0.18 | 1.01 | 0.91 |
23 | Did you feel irritable? | -0.11 | 0.17 | 0.88 | 1.1 |
13 | Have you lacked appetite? | -0.14 | 0.17 | 0.88 | 1.19 |
4 | Do you need to stay in bed or a chair during the day? | -0.17 | 0.17 | 1.16 | 1.1 |
1 | Trouble doing strenuous activities, like carrying a heavy bag or a suitcase? | -0.19 | 0.17 | 0.89 | 1.03 |
9 | Have you had pain? | -0.22 | 0.17 | 1.21 | 0.96 |
21 | Did you feel tense? | -0.25 | 0.17 | 0.87 | 0.84 |
25 | Have you had difficulty remembering things? | -0.33 | 0.17 | 0.75 | 1.08 |
2 | Do you have any trouble taking a long walk? | -0.41 | 0.16 | 1.09 | 1.09 |
22 | Did you worry? | -0.68 | 0.16 | 0.71 | 1.17 |
11 | Have you had trouble sleeping? | -0.72 | 0.16 | 1.31 | 0.84 |
26 | Physical condition or medical treatment interfered with your family life? | -0.75 | 0.16 | 1.41 | 0.98 |
24 | Did you feel depressed? | -0.77 | 0.16 | 0.64 | 1 |
27 | Physical condition or medical treatment interfered with your social activities? | -0.82 | 0.16 | 1.14 | 0.81 |
10 | Did you need to rest? | -0.84 | 0.15 | 0.49 | 1.13 |
12 | Have you felt weak? | -0.99 | 0.15 | 0.41 | 1.26 |
28 | Physical condition or medical treatment caused you financial difficulties? | -1.02 | 0.15 |
1.74
| 1.09 |
18 | Were you tired? | -1.08 | 0.15 | 0.49 | 0.88 |
Procedures for data simulation
1. Alpha 95% CIs by both observed and expected scores
2. Generating expected response data sets by simulation
3. Item-by-item skewness analysis by a bootstrapping procedure
Statistical analyses
Results
Item difficulties of EORTC QLQ-C30
Alpha values for different person numbers
Response Types | Numbers of Person | Test Reliability | 95% Confidence Interval | |
---|---|---|---|---|
Lower Bound
|
Upper Bound
| |||
Observed scores | 115 | 0.909 | 0.883 | 0.931 |
230 | 0.909 | 0.891 | 0.925 | |
345 | 0.909 | 0.894 | 0.922 | |
Expected scores | 115 | 0.920 | 0.898 | 0.94 |
230 | 0.920 | 0.905 | 0.934 | |
345 | 0.920 | 0.908 | 0.932 |
Skewness analysis with 95% CI on misfitting items
Overall skewness analysis with 95% CI across items
Difficulty | Skew_ Exp. | Observed | Expected | Skew_ Obs. | |
---|---|---|---|---|---|
Difficulty |
0.72
| 0.55 | -21.72 | -20.93 | 0.64 |
Skew_Exp. | 0.95 |
0.46
| -16.03 | -16.07 | 0.51 |
Observed | -0.98 | -0.90 |
684.07
| 656.29 | -18.28 |
Expected | -0.97 | -0.93 | 0.98 |
650.99
| -17.58 |
Skew_Obs. | 0.95 | 0.94 | -0.88 | -0.87 |
0.63
|