| MEASUREMENT PROPERTIES | |
| Limitations | |
| Observations |
Nearly all of the studies of axial examination methods have primarily enrolled patients with r-AxSpA. This has significant implications for these particular tools because they may have different psychometric properties (in particular responsiveness) in patients who do not have structural damage (ie, nr-axSpA). |
| 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) |
Although reliability has been good in some studies among physiotherapists (ICC = 0.97) and physicians (ICC = 0.92-0.97), other studies have found very poor reliability, particularly over time. |
| 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 |
Not Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Not Tested |
| Brief Description | |
| C. Criterion validity | Not Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
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