| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach's alpha = 0.87 |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
When repeated testing 1 week apart was performed, it demonstrated a correlation of 0.88 and an interclass correlation coefficient of 0.90 (P < 0.01) |
| C. Reliability interobserver or Measurement error | Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
14.8% SDD as percentage of maximum value of outcome |
| 2. VALIDITY | |
| A. Content validity: face validity | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
The RAPID3 score is composed of ACR core set measures used to assess the efficacy of disease‐modifying antirheumatic drugs. |
| B. Construct Validity: Structural validity |
Not Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description | |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
The RAPID3, RAPID4MDJC, RAPID4PTJC, and RAPID5 scores demonstrate Spearman's correlation coefficients as compared to the DAS28 between 0.69 and 0.73. When comparing RAPID3 to ACR 20% improvement criteria and the DAS in a randomized controlled trial, the κ ranged between 0.62 and 0.64, indicating similar sensitivity in identification of active treatment from placebo |