Number (percentage) of participants reporting global improvement or achieving an improvement of 1.8 NRS units in the primary outcome (change in knee pain on walking; baseline minus 6 months), and relative risks* and risk differences*
| Motion control shoes (n=18) | Neutral shoes (n=22) | Relative risk (95% CI)† | P value | Risk difference (95% CI)‡ | P value | |
| Improved pain§ | 6/18 (33) | 10/22 (46) | 1.36 (0.61 to 3.01) | 0.45 | 0.12 (−0.18 to 0.42) | 0.44 |
| Improved function§ | 4/18 (22) | 7/22 (32) | 1.43 (0.50 to 4.10) | 0.50 | 0.10 (−0.18 to 0.37) | 0.49 |
| Improvement >1.8 NRS units¶ | 9/18 (50) | 14/22 (64) | 1.28 (0.74 to 2.24) | 0.38 | 0.14 (−0.16 to 0.44) | 0.36 |
*Relative risk and risk difference adjusted for radiographic severity (Kellgren and Lawrence grade).
†Relative risks <1 favour the motion control shoe group.
‡Risk differences <0 favour the motion control shoe group.
§Rated using 7-point scales with the terminal descriptors ‘much worse’ to ‘much better’, with participants indicating ‘moderately better’ or ‘much better’ classified as improved.
¶Improvement of >1.8 NRS units chosen as this is the minimum clinically important difference in the primary outcome, change in knee pain on walking (baseline–6 months).
NRS, Numeric Rating Scale.