| 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) |
Intraobserver reliability was 0.92 (95% CI 0.83 to 1.00) for VDI. |
| C. Reliability interobserver or Measurement error | Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
Interobserver reliability (assessed by intraclass correlation coefficient (ICC)) was 0.94 (95% CI 0.89 to 0.98) for VDI. |
| 2. VALIDITY | |
| A. Content validity: face validity | Not Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
|
| B. Construct Validity: Structural validity |
Not Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description | |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
Relapse was established as gold standard. Relapse group versus the non-relapse group (6.5 ± 2.3 vs 4.0 ± 1.0; p = 0.02) at 5 years |