| MEASUREMENT PROPERTIES | |
| Limitations | |
| Observations |
Only in Chinese |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach’s alpha estimated internal consistency, which was .95 for the total scale, and ranged from .85 to .94 for the three subscales. |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
Stability of the instrument was determined by having participants repeat the questionnaire a second time 4 weeks later. A total of 328 questionnaires (88%) were obtained. Pearson’s correlation coefficient for the total scale was .88 (p < .01), and each subscale ranged from .83 to .89 (p < .01). ICC for the total scale was .95 (p < .01), and each subscale ranged from .85 to .94, and achieved statistical significance (p < .01). |
| 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 | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
Ten Taiwanese volunteers with knee OA agreed to complete the instrument, simultaneously reviewing it for clarity, item comprehension, and ease of response. Items were scored on a 4-point scale ranging from 1 (very inadequate) to 4 (very adequate). The Content Validity Index for an item was the proportion of experts who rated the item as a 4. The content validity index was 0.83. |
| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Not Tested |
| Brief Description |
Construct validity was assessed by exploratory factor analysis. Exploratory factor analysis showed the Kaiser–Meyer–Olkin (KMO) measure of sampling adequacy was .91. Principal axis factor analysis with varimax rotation extracted three factors, which accounted for 53.19% of the total variance |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
The Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Short-Form Health Survey (SF-36) were used to evaluate the criterion validity of the SMNKOA scale (see correlation coefficients above). |