| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Internal consistency of all 13 items now included was 0.84 Two samples were assessed. Cronbach’s alpha of the scale in sample 1 was 0.73, indicating acceptable internal consistency. Cronbach’s alpha could be increased up to 0.84 by removing seven items (i.e. 13, 8, 12, 4, 2, 6 and 11). Removing any additional items would no longer lead to an increase in Cronbach’s alpha. In sample 2, internal consistency was slightly lower than in sample 1 (Cronbach’s alpha 0.69) but could be increased to 0.82 by removing eight items (i.e. 8, 13, 12, 2, 6, 11, 4 and 7). These are largely the same items as identified for removal in sample 1 but removed in a slightly different order. The only other -and additional- item excluded in sample 2 was item 7. |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
Test-retest reliability (based on the 13 items) was computed for the subset of sample A, and the ICC was high at 0.85. |
| 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 | Tested |
| Cross-cultural validity | Not Tested |
| Brief Description |
The eighteen items loaded on six factors (eigenvalues > 1). Factor one explained 28% of the variance, and factors two and three only explained 9% each. Factor four, five and six explained 8%, 7% and 6% respectively. Based on the scree plot, they evaluated a one-, two- and three-factor model. In the two-factor model, most items loaded on factor one and no general construct could be observed for the items 4, 8, and 11 that loaded on factor two in the two-factor model. The three-factor model did not point to any clearly interpretable factors. In addition, based on average inter-item correlations and item-total correlations and a cut-off correlation for retention of 0.3, items 8, 12 and 13 should potentially be removed.
Confirmatory Factor Analysis (CFA) was performed to examine the previously determined one-factor structure of the HRAS-13. In sample 1, the Comparative Fit Index was 0.78, the Root Mean Square Error of Approximation (RMSEA) was 0.10 and the Standardized Root Mean Square Residual (SRMR) was 0.07. Based on these statistics the model fit is not good, and a one-factor model does therefore not seem accurate. In sample 2, the CFI was 0.65, the RSMEA and the SRMR were 0.13 and 0.09, respectively. Therefore, the one factor model performed worse in sample 2 than in sample 1 |
| C. Criterion validity | Not Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
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