| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations |
Dutch and English |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach´s α= 0.89 |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
Pearson correlation in 28 stable patients who completed two questionnaires with a 1-month-interval: 0.78 for the number of symptoms and 0.87 for the total distress |
| 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) |
Items were solicited from the literature and physicians treating SLE patients were asked to generate items. After a panel discussion the chosen items were reviewed by 20 lupus patients |
| B. Construct Validity: Structural validity |
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) |
Correlation of SSC total distress and other QoL instruments:
|