Table 3.
Effect sizes from baseline to 6 weeks (n = 22) and relative efficiency
| Instrument | Mean changea (95%CI) | p | Effect size | Relative efficiencyb | Relative efficiency rank |
|---|---|---|---|---|---|
| Pain - right knee | −2.67 (−4.10 to −1.23) | < 0.01 | 0.79 (medium) | 1.00 | 1 |
| Pain - left knee | −1.78 (− 2.84 to −0.72) | < 0.01 | 0.51 (medium) | 0.82 | 2 |
| EQ-5D index | 0.23 (0.07 to 0.39) | 0.01 | 0.85 (large) | 0.59 | 3 |
| Pain - lower back | −1.89 (−3.25 to −0.53) | 0.01 | 0.77 (medium) | 0.56 | 4 |
| KOOS physical functionc | −9.87 (−19.19 to −0.55) | 0.04 | 0.74 (medium) | 0.35 | 5 |
| Pain - right hip | −1.17 (−2.83 to 0.50) | 0.16 | 0.39 (small) | 0.14 | 6 |
| EQ-5D VAS | 5.53 (−4.52 to 15.57) | 0.26 | 0.26 (small) | 0.09 | 7 |
| Pain - left hip | −0.44 (−1.78 to 0.89) | 0.49 | 0.19 (small) | 0.03 | 8 |
aMean change = 6-week post-operative score minus baseline score; positive change represents improvement for the EQ-5D index and EQ-5D VAS; negative change represents improvement for pain scores, and KOOS-PS score; p < 0.05 indicates a statistically significant change
bRelative efficiency < 1.00 indicates that the instrument is less efficient than the ‘Pain - right knee’ score in detecting change after joint replacement surgery
cKOOS physical function scores collected from knee participants only; HOOS physical function scores are not reported as too few hip participants completed both baseline and 6 week questionnaires (n = 3)