| MEASUREMENT PROPERTIES | |
| Limitations | >=5 European languages (English) |
| Observations |
61 language versions available, 9 of these are fully validated and published. |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach' alpha: 0.91 |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
The test-retest Spearman rank correlation coefficient was 0.89. |
| 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) |
The content of the PsAQoL was derived from unstructured, qualitative interviews conducted with patients with PsA in their own homes. The interviews, which were audio recorded, were informal, focused conversations and were designed to explore how PsA affects the lives of patients. |
| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description |
Unidimensionality was assessed by Rash analysis and differential item functioning (DIF). |
| C. Criterion validity | Not Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
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