Table 2.
Test-retest reliability (intraclass correlation coefficient [ICC]) and internal consistency (Cronbach’s alpha [CA]) for the total score of the Dutch New Knee Society Scoring System and for the different domains
| Domain | Test 1 | Test 2 | ICC | 95% CI | CA | ||
|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | ||||
| Symptoms (3 items)/25 | 12.0 | 5.2 | 11.6 | 5.0 | 0.92 | 0.86–0.95 | 0.96 |
| Satisfaction score (5 items)/40 | 14.5 | 9.1 | 14.9 | 8.5 | 0.73 | 0.60–0.85 | 0.84 |
| Expectation score (3 items)/15 | 11.9 | 2.5 | 11.7 | 2.6 | 0.84 | 0.77–0.92 | 0.91 |
| Functional activity (4 items)/30 | 11.5 | 9.0 | 12.2 | 8.3 | 0.92 | 0.87–0.95 | 0.96 |
| Standard activities (6 items)/30 | 13.3 | 5.7 | 13.9 | 6.1 | 0.83 | 0.76–0.91 | 0.91 |
| Advanced activities (5 items)/25 | 4.8 | 5.1 | 4.9 | 4.8 | 0.78 | 0.69–0. 89 | 0.87 |
| Discretionary activities (3 items)/15 | 5.2 | 3.4 | 5.8 | 3.7 | 0.76 | 0.66–0.88 | 0.86 |
| Total functional score (18 items)/100 | 35.9 | 18.7 | 37.3 | 18.3 | 0.87 | 0.78–0.93 | 0.93 |
| Total score/180 | 71.9 | 24.6 | 74.0 | 24.1 | 0.82 | 0.69–0.90 | 0.93 |
| Total score/100) | 40.7 | 13.9 | 41.8 | 13.4 | 0.82 | 0.70–0.89 | 0.90 |
CI = confidence interval.