Table 6 Item characteristics of the IPS in subgroups of patients and staff
Subgroup | N | Discrimination (corrected item-total correlation) range | Difficulty (mean; range 1–4) | Internal consistency (Cronbach’s alpha) |
|---|---|---|---|---|
Patients | ||||
Indication group | ||||
- Somatic | 345 | .556-.770 | 3.43-3.72 | .878 |
- Psychosomatic | 191 | .473-.763 | 3.21-3.47 | .853 |
Gender | ||||
- Male | 334 | .549-.785 | 3.40-3.58 | .875 |
- Female | 198 | .537-.787 | 3.40-3.71 | .882 |
Education | ||||
- Low | 233 | .536-.799 | 3.51-3.67 | .864 |
- Medium | 177 | .556-.802 | 3.32-3.60 | .898 |
- High | 106 | .558-.721 | 3.29-3.58 | .846 |
Age groups | ||||
- 18-40 | 97 | .414-.757 | 3.31-3.51 | .855 |
- 41-60 | 276 | .540-.772 | 3.35-3.59 | .865 |
- >60 | 151 | .515-.775 | 3.67-3.83 | .867 |
Staff | ||||
Indication group | ||||
- Somatic | 198 | .506-.736 | 2.92-3.31 | .872 |
- Psychosomatic | 52 | .510-.713 | 2.56-2.96 | .834 |
Gender | ||||
- Male | 94 | .644-.791 | 2.82-3.12 | .898 |
- Female | 164 | .670-.741 | 2.83-3.27 | .856 |
Professionals | ||||
- Physicians | 49 | .741-.781 | 3.00-3.47 | .916 |
- Nursing staff | 48 | .294-.758 | 2.63-3.08 | .871 |
- Psychosocial therapists | 67 | .356-.567 | 2.73-3.98 | .746 |
- Physical therapists | 50 | .444-.816 | 2.88-3.41 | .867 |
- Other professionals | 37 | .507-.715 | 2.74-3.32 | .824 |
Age groups | ||||
- 17 – 35 | 52 | .480-.732 | 2.76-3.46 | .806 |
- 36 - 55 | 170 | .504-.775 | 2.84-3.15 | .883 |
- 56 and older | 38 | .675-.868 | 2.88-3.24 | .906 |