| MEASUREMENT PROPERTIES | |
| Limitations | English only |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
average inter-item correlations ranged from 0.69 to 0.93 average item-total score correlations ranged from 0.78 to 0.95, and internal consistency reliabilities coefficient α estimates ranged from 0.91 to 0.98 |
| B. Reliability intraobserver or test-retest | Not Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
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| C. Reliability interobserver or Measurement error | Not Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
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| 2. VALIDITY | |
| A. Content validity: face validity | Not Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
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| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Not Tested |
| Cross-cultural validity | Not Tested |
| Brief Description |
Focus groups were tested in order to develop the domains of importance to patients with SSc |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
the HAQ, correlations of each SBI scale ranged from 0.3–0.6 and were statistically significant. For the SF-36, higher SBI scores negatively correlated with the SF-36 for both the mental and physical components |