| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
α = 0.78 for the “spine mobility” dimension. α = 0.80 – 0.91for the other 12 dimensions |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
ICC = 0.69 for the “spine mobility” dimension. ICC = 0.90 for the physical component. ICC = 0.70 – 0.90 for the other 4 components |
| 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 | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
Developed using a focus group technique with 7 patients and 3 physicians. They were presented with the S-HAQ for functional disability in AS and were instructed to select appropriate items or to generate items to supplement the comprehensive original AIMS2. |
| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description |
Explored through principal component analyses (PCA). Work items were excluded from PCA because of missing items. After exclusion of work items, PCA identified the remaining 12 dimensions, explaining 74.1% of the total variance, maintaining the dimensionality of the 11 original AIMS2 dimensions and an additional spine dimension. |
| C. Criterion validity | Not Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
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