| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach's alphas ranged from 0.72-0.79 |
| 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 | Not Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
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| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Not Tested |
| Cross-cultural validity | Not Tested |
| Brief Description |
Factor analysis revealed that most items corresponded to the a priori described groups (precontemplation stage (Pre), the contemplation (Cont) and the action (Act) stage), while some items were not loading on the presumed factor (factor loading below 0.35). In each subgroup some items were deleted, resulting in a 15-item questionnaire. Repeated FA with 15 item scale: 3 factors explained 45% of variance. |
| C. Criterion validity | Not Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
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