| MEASUREMENT PROPERTIES | |
| Limitations | English only |
| 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) |
The SAFE-Part A was mailed to 24 participants on two separate occasions, separated by 7 days. Although all participants returned the first copy of the SAFE Part A, only 18 participants returned the second copy, resulting in a paired data response rate of 83 %. All three subscales of the SAFE-Part A were found to have between excellent and perfect 1-week testeretest reliability, with ICC values ranging between 1.00 and 0.96. |
| 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) |
Podiatrists, rheumatologists and patients with RA-related foot problems participated in its development. For the SAFE-Part A, there was a very good agreement between item ratings given by the 32 clinicians, with an ICC of 0.827 (95% confidence interval [CI]= 0.779-0.868). Most of the items had a median content validity index of between 8.0 and 10.0 (87%). This suggests that there was a strong consensus on the levels of importance and relevance of the different potential items for the scale. |
| 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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