| 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) |
Results from its development and validation indicate that the Brief IPQ has good test–retest reliability (Pearson 0.49-0.70 at 3 weeks), and there are moderate to good associations between the Brief IPQ and the IPQ-R on all the equivalent dimensions. The lowest associations are between the control dimensions. |
| 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) |
The Brief IPQ allows very simple interpretation of scores: increases in item scores represent linear increases in the dimension measured. |
| B. Construct Validity: Structural validity |
Not 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) |
Five longitudinal studies administered the Brief IPQ at baseline and examined differences between groups. Regarding rheumatic diseases, compared to patients with autoimmune thyroid disease, individuals with chronic fatigue syndrome reported shorter timeline beliefs, greater illness concerns and lower treatment control perceptions (Dickson et al., 2009). |