Introduction
Materials and methods
Cross-cultural translation
Psychometric evaluation
Participants
Measures
Data analysis
Results
Patient characteristics
Characteristic | OA
n = 209 | FM
n = 29 |
P
| Total
N = 238 |
---|---|---|---|---|
Age, years | 62.6 ± 10.1 | 42.4 ± 14.4 | <0.001 | 60.1 ± 12.6 |
Sex, female | 169 (80.9 %) | 25 (86.2 %) | N.S. | 194 (81.5 %) |
Disease duration, years | 10.9 ± 10.9 | 10.2 ± 10.1 | N.S. | 10.8 ± 10.8 |
Ethnicity, Dutch | 198 (94.7 %) | 27 (93.1 %) | N.S. | 225 (94.5 %) |
Self-management training, yes | 13 (6.2 %) | 9 (31.0 %) | <0.001 | 22 (9.2 %) |
Marital status | ||||
Not married/not living together | 4 (1.9 %) | 6 (20.7 %) | <0.001 | 10 (4.2 %) |
Married/living together | 158 (75.6 %) | 20 (69.0 %) | 178 (74.8 %) | |
Widowed/divorced | 45 (21.6 %) | 3 (10.3 %) | 48 (20.2 %) | |
Education | ||||
Low | 127 (60.7 %) | 11 (37.9 %) | 0.070 | 138 (58.0 %) |
Medium | 44 (21.1 %) | 14 (48.3 %) | 58 (24.4 %) | |
High | 35 (16.8 %) | 4 (13.8 %) | 39 (16.4 %) | |
Occupational status | ||||
Full-time employed | 25 (12.0 %) | 2 (6.9 %) | <0.001 | 27 (11.3 %) |
Part-time employed | 49 (23.4 %) | 12 (41.4 %) | 61 (25.6 %) | |
Homemaker | 51 (24.4 %) | 5 (17.2 %) | 56 (23.5 %) | |
School | 1 (0.5 %) | 4 (13.8 %) | 5 (2.1 %) | |
Unemployed/disabled/retired | 80 (38.3 %) | 6 (20.6 %) | 86 (36.1 %) | |
EC-17 (range 0–100) | 68.9 ± 16.3 | 62.3 ± 14.1 | 0.040 | 68.1 ± 16.1 |
PEPPI-5 (range 5–25) | 18.7 ± 4.3 | 16.8 ± 3.1 | 0.005 | 18.5 ± 4.2 |
GSES (range 12–60) | 42.8 ± 6.3 | 42.9 ± 7.5 | N.S. | 42.8 ± 6.5 |
AIMS2 Support (range 0–10) | 3.7 ± 2.5 | 4.7 ± 2.4 | 0.039 | 3.8 ± 2.5 |
SF-36 PCS (range 0–100) | 36.0 ± 9.2 | 35.7 ± 6.4 | N.S. | 35.9 ± 8.9 |
SF-36 MCS (range 0–100) | 49.0 ± 10.6 | 43.7 ± 12.0 | 0.015 | 48.4 ± 10.9 |
NRS Pain (range 0–10) | 5.7 ± 2.0 | 7.1 ± 1.2 | <0.001 | 5.8 ± 2.0 |
Distributional properties
Unidimensionality
Item | Factor loading | Item difficulty in logits (SE) | Infit MNSQ | Outfit MNSQ | Absolute DIF in logits | ||
---|---|---|---|---|---|---|---|
Sexa
| Ageb
| Disease durationc
| |||||
16. I can negotiate with the healthcare system about what to do to manage my disease | 0.80 | 0.67 (0.09) | 0.98 | 1.01 | −0.14 | 0.15 | −0.35 |
13. I feel a sense of control over my disease | 0.73 | 0.56 (0.10) | 1.09 | 1.15 | −0.25 | 0.28 | 0.21 |
10. I am able to play the role I want to in my healthcare team | 0.71 | 0.36 (0.10) | 1.06 | 1.12 | 0.11 | −0.03 | 0.00 |
1. I know who can help me judge the quality of the information I receive about my disease | 0.66 | 0.36 (0.09) | 1.19 | 1.33 | −0.09 | −0.29 | −0.05 |
15. I can negotiate with others about what we need to do to manage my disease | 0.85 | 0.30 (0.10) | 0.74 | 0.75 | −0.03 | 0.06 | 0.00 |
17. I can organise my life to act on decisions about how to manage my disease | 0.82 | 0.22 (0.10) | 0.86 | 0.80 | −0.15 | 0.34 | −0.09 |
11. I know who to work with to meet my health needs | 0.76 | 0.19 (0.10) | 0.91 | 0.88 | −0.25 | 0.14 | 0.00 |
12. I can be assertive to get what I need to meet my health needs (for example, information and treatments) | 0.83 | 0.18 (0.10) | 0.78 | 0.74 | 0.10 | 0.11 | −0.13 |
6. I can set realistic goals about the management of my disease | 0.67 | −0.01 (0.11) | 1.09 | 1.03 | 0.05 | −0.23 | −0.02 |
4. I can be clear about what is important in my life when I make decisions about my disease | 0.68 | −0.08 (0.12) | 1.01 | 1.03 | 0.16 | −0.20 | 0.18 |
9. I have built an open and trusting relationship, based on mutual respect, with my healthcare providers | 0.70 | −0.15 (0.09) | 1.13 | 1.20 | −0.31 | 0.42 | 0.05 |
7. I can express my concerns well to healthcare providers | 0.74 | −0.26 (0.10) | 0.97 | 1.01 | 0.35 | 0.24 | −0.22 |
5. I can weigh the pros and cons of a decision about my disease | 0.70 | −0.35 (0.11) | 1.02 | 0.98 | 0.31 | −0.18 | 0.23 |
8. I know how to ask good questions about my health and my disease | 0.77 | −0.37 (0.11) | 0.92 | 0.92 | 0.05 | −0.31 | −0.17 |
14. I feel confident in making decisions about my health | 0.76 | −0.39 (0.11) | 0.97 | 0.94 | 0.00 | 0.33 | −0.11 |
3. I know how to adapt general health information to my own situation | 0.68 | −0.57 (0.11) | 1.00 | 1.03 | 0.09 | −0.48 | 0.46 |
2. I understand the information I receive about my disease | 0.64 | −0.68 (0.11) | 1.17 | 1.09 | 0.29 | −0.80* | 0.21 |
Rasch measurement properties
Test–retest reliability
External construct validity
Measure | Expected r
| Observed r
|
---|---|---|
PEPPI-5 | 0.5–1.0 | 0.55** |
GSES | 0.3–0.5 | 0.26** |
AIMS2 Support | 0.3–0.5 | −0.34** |
SF-36 MCS | 0.3–0.5 | 0.39** |
SF-36 PCS | 0.0–0.3 | 0.14* |
NRS Pain | 0.0–0.3 | −0.21** |