Table 2.
Construct domains of the scales and their relation to the transition items, and floor, ceiling and reliability data (n=190)
| Instrument | Scale | Items | Domain/transition item content | Floor % | Ceiling % | Correlation | ICC |
| WOMAC | Pain | 5 | Pain | – | – | 0.43 | 0.70 |
| SF-36 | Bodily pain | 2 | Pain | – | 0.5 | 0.42 | 0.72 |
| WOMAC | Function | 17 | Walking plus dressing/personal hygiene | – | – | 0.49 | 0.74 |
| SF-36 | Physical functioning | 10 | Walking plus dressing/personal hygiene | – | – | 0.36 | 0.86 |
| WOMAC | Factor standing/walking | 4 | Walking | – | 1.1 | 0.39 | 0.79 |
| WOMAC | Stiffness | 2 | Joint mobility | – | 3.7 | 0.37 | 0.55 |
| SF-36 | Role physical | 4 | Household chores plus work | 65.8 | 5.4 | 0.26 | 0.44 |
| SF-36 | Vitality | 4 | Fatigue | – | 1.1 | 0.18 | 0.03 |
| SF-36 | Social functioning | 2 | Social activities (performance) | – | 23.7 | 0.20 | 0.80 |
| SF-36 | Mental health | 5 | Mood/mental health | – | 1.1 | 0.31 | 0.70 |
| SF-36 | General health | 6 | Health in general | – | 0.5 | 0.35 | 0.88 |
Ceiling, proportion of patients with best possible score (%) at baseline; correlation, Spearman rank correlation between the score difference (baseline to follow-up) and the transition item; floor, proportion of patients with worst possible score (%) at baseline; ICC, intraclass correlation coefficient for test–retest reliability out of the literature20 21 27; SF-36, Short Form 36; WOMAC, Western Ontario and McMaster Universities Index.