| MEASUREMENT PROPERTIES | |
| Limitations | >=5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
The LLFI has high internal consistency (Cronbach’s = 0.91) |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
High test–retest reliability (ICC2.1 = 0.97) |
| C. Reliability interobserver or Measurement error | Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
Standard error of the measurement= 2.84 |
| 2. VALIDITY | |
| A. Content validity: face validity | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
Face and content validity were assessed through the patient focus group, panel feedback, and readability scores. |
| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description |
Factor analysis indicated a single-factor structure for the LLFI, with all three a priori criteria met: suitable scree plot, eigenvalue 1.0, and variances 10% |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
Criterion-related validity was assessed through Pearson r coefficient for concurrently completed LLFI and LEFS responses, r= 0.88. |