| MEASUREMENT PROPERTIES | |
| Limitations | >=5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach's alpha of the SSS was 0.65 and of the FS was 0.71. |
| 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) |
Two patients felt insecure where to indicate pain in the elbows and knees in the WPI because these pain sites were not mentioned. Two physicians felt puzzled by the different time frames of the FSQ. One physician wondered why abdominal pain was assessed both in the SSS and in the WPI |
| 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) |
1411 (85.5%) participants of the total sample met the FSDC of FMS. 1351 (95.7%) reported a WPI ≥7 and a SSS ≥5 and 60 (4.4%) reported a WPI 3–6 and a SSS ≥9. The diagnosis of FMS according to the ACR 1990 criteria was reevaluated at the date of appointment in 128 patients in 4 study centres with previously or actually diagnosed FMS. The mean of TPC was 13.8 (SD 3.5) (range 0–18). 107/128 (83.6%) participants met the ACR 1990 classification criteria of FMS. The concordance rate of the FSDC and ACR 1990 criteria was 72.7% |