Psychometric properties of the MSIS-29 physical and psychological scales in each population
| Psychometric property | Community-based sample n = 172 | Outpatient sample n = 102 | ||
|---|---|---|---|---|
| MSIS-29 physical | MSIS-29 psychological | MSIS-29 physical | MSIS-29 psychological | |
| n, number; SD, standard deviation; SE, standard error; SEM, standard error of mean; CI, confidence interval. | ||||
| Data quality | ||||
| Item missing data (%) | 0–2.8 | 0–1.9 | 0–1.9 | 0–0.98 |
| Computable scores (%) | 100 | 100 | 100 | 100 |
| Scaling assumptions | ||||
| Item mean scores | 1.62–3.26 | 1.62–2.63 | 1.83–3.14 | 1.95–2.71 |
| Item SD | 1.11–1.59 | 0.99–1.34 | 1.16–1.65 | 1.03–1.42 |
| Item-total correlation | 0.58–0.89 | 0.32–0.81 | 0.59–0.82 | 0.0.58–0.76 |
| Acceptability | ||||
| Scale range | 0–100 | 0–100 | 0–100 | 0–100 |
| Score range | 0–95 | 0–86.1 | 0–98.68 | 0–97.22 |
| Mean score (SD) | 38.85 (25.3) | 28.7 (21.3) | 34.5 (25.5) | 32.3 (23.6) |
| Mean score (SE) | 1.94 | 1.63 | 2.54 | 2.34 |
| Floor/ceiling effects (%) | 1.4/0 | 1.4/0.9 | 4.95/0 | 6.86/0 |
| Skewness | 0.26 | 0.86 | 0.526 | 0.626 |
| Reliability | ||||
| Cronbach’s alpha | 0.9641 | 0.8919 | 0.9569 | 0.8966 |
| SEM | 5.0 | 9.2 | 5.29 | 7.59 |
| 95% CI | +/−9.8 | +/−18 | +/−10.4 | +/−14.9 |