| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Not Tested |
| Cronbach's (Describe) | |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
ICC=0.50–0.61 |
| C. Reliability interobserver or Measurement error | Not Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
|
| 2. VALIDITY | |
| A. Content validity: face validity | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
constructed by a recognized specialist in SSc, one experienced rheumatologist and one physiotherapist working with scleroderma patients. There were no major problems with comprehension, the patients found the questionnaire 100% understandable, relevant to their disease and feasible |
| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Not Tested |
| Cross-cultural validity | Not Tested |
| Brief Description |
All thickness-related scores were sorted into the same factor by principal component analysis. Conversely, skin thinness scores were sorted into a distinct factor. |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
Gold standard mRSS. The baseline mRSS correlated significantly with the 17-area thickness score (rho=0.435), overall thickness score (rho=0.332) and VAS -thickness score (rho=0.239) |