| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach’s alpha of 0.919 |
| B. Reliability intraobserver or test-retest | Not Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
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| 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) |
MISS questionnaire satisfies the criteria of feasibility, face validity, and content validity since it is short and easy to complete by patients or parents, easy to interpret by physicians, and contains all relevant aspects of MTX intolerance as established by a consensus of expert rheumatologists |
| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Not Tested |
| Cross-cultural validity | Tested |
| Brief Description |
All items of the MISS questionnaire were discriminative between patients with and those without MTX intolerance as determined by the gold standard, with the exception of “vomiting when thinking of MTX” (associative vomiting) and the entire domain of oral pain. |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
The area under the ROC curve was 0.90 (95% CI 0.83–0.96), indicating that 90% of the patients were classified correctly with the MISS questionnaire. 80% of the patients who were tolerant to MTX according to the gold standard would indeed be identified as MTX tolerant according to the MISS questionnaire. |