| MEASUREMENT PROPERTIES | |
| Limitations | <5 European languages (English) |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
0.88 |
| 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) |
The HAQ-II was developed to be a short replacement for the HAQ and was created using an item bank and Rasch analysis to best balance item fit, scale length, and item spacing in an attempt to correct the floor effects seen with earlier modifications of the HAQ. |
| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description |
The HAQ-II was designed using Rasch analysis and was found to measure disability over a longer scale than the HAQ, and has no nonfitting items and no gaps between items. The HAQ-II is not a true unidimensional tool and includes 9 items assessing functional limitations and 1 measure of disability (“doing outside work”). |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
The HAQ-II and HAQ are highly correlated (r= 0.92) with average HAQ-II scores shown to be only minimally lower (by 0.02–0.04) than HAQ scores. Notably, HAQ and HAQ-II have been shown not to be interchangeable in an individual patient. |