| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations |
English, Spanish (applicable to Spain, US and Latin American), Portuguese (Portugal and Brazil) |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach's α=0.72 |
| B. Reliability intraobserver or test-retest | Not Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
|
| C. Reliability interobserver or Measurement error | Not Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
|
| 2. VALIDITY | |
| A. Content validity: face validity | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
Questions based on SDI. Several clinical researchers, clinicians and literacy experts reviewed the translation, attempting to target an 8 grade reading level. |
| B. Construct Validity: Structural validity |
Not Tested |
| Hypotheses-testing | Not Tested |
| Cross-cultural validity | Not Tested |
| Brief Description |
The strongest correlates of the LDIQ were: Comorbidity index: r=0.45 SF-36 PCS r=0.43 Disability status r=0.37 |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
The GS was the physician reported SDI. Sensitivity: 53.3% Specificity: 94.6% Agreement: 93.2% Lower agreement in the mail-based validation |