| MEASUREMENT PROPERTIES | |
| Limitations | >=5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Not Tested |
| Cronbach's (Describe) | |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
The pain VAS has good test-retest reliability, especially among literate patients (r=0.94, P=0.001) compared to illiterate patients (r=0.71, P=0.001) before and after visiting a rheumatology outpatient clinic. It has also been found to be highly reliable for acute abdominal pain (ICC=0.99, 95%CI 0.989 to 0.992) and moderately to highly reliable for assessing disability in patients with chronic musculoskeletal pain. |
| C. Reliability interobserver or Measurement error | Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
Same-day (Pearson's correlation coefficient 0.85, 95%CI 0.78–0.88) and 7 day test-retest reliability (Pearson's correlation coefficient 0.64, 95%CI 0.43–0.78) were significantly correlated |
| 2. VALIDITY | |
| A. Content validity: face validity | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
The pain VAS has been found to be acceptable to patients. |
| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description |
Construct validity in this study was demonstrated by a correlation between higher levels of pain being associated with higher CRP levels (one way ANOVA F = 6.09, df=4, p = 0.015). |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
Because there is no gold standard for measuring pain, criterion validity cannot be assessed. |