| MEASUREMENT PROPERTIES | |
| Limitations | >=5 European languages (English) |
| Observations |
KOOS-12 translations can be developed in any language for which a KOOS translation is available, by selecting the KOOS-12 items from the full-length KOOS translation |
| 1. RELIABILITY | |
| A. Internal Consistency | Not Tested |
| Cronbach's (Describe) |
Internal consistency reliability (Cronbach’s alpha) of KOOS-12 scales ranged from 0.75-0.82 (KOOS-12 Pain), 0.78-0.82 (KOOS-12 Function) and 0.80-0.84 (KOOS-12 QOL). Internal consistency reliability of the KOOS-12 Summary impact score ranged from 0.90 to 0.93 before to 6-12 months after TKR The pain, function, and quality of life domains of the HOOS-12 and KOOS-12 demonstrated excellent internal consistency reliability (person separation index: 0.80-0.93) |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
The intra-class correlation coefficient of KOOS-12 scales ranged from 0.60 to 0.71 |
| C. Reliability interobserver or Measurement error | Not Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
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| 2. VALIDITY | |
| A. Content validity: face validity | Not Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
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| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description |
Convergent and discriminant validity and responsiveness to TKR of the KOOS-12 Pain, Function and QOL scales were satisfactory and reached similar conclusions as comparable KOOS scales. The KOOS-12 Summary score had high effect sizes and standardized response means post-TKR A mismatch between item difficulty and person ability scores at the highest end of the HOOS-12 and KOOS-12 scales contributed to post-operative ceiling effects (mean logit for HOOS-12: 3.57; KOOS-12: 2.58; ≈0 indicates well-targeted scale). |
| C. Criterion validity | Not Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
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