Mean (SD) scores on continuous outcome measures across time by shoe group, mean change within groups and difference* in change between groups for continuous outcomes, using complete case data
| Baseline | 6 months | Mean (SD) change within groups | Difference in change between groups* | |||||
| Baseline minus 6 months | Baseline to 6 months | |||||||
| Motion control shoes (n=18) | Neutral shoes (n=22) | Motion control shoes (n=18) | Neutral shoes (n=22) | Motion control shoes (n=18) | Neutral shoes (n=22) | Mean difference (95% CI) | P value | |
| Primary outcome | ||||||||
| Average knee pain on walking (NRS)† | 5.7 (1.1) | 5.4 (1.0) | 4.3 (2.2) | 3.7 (2.2) | 1.4 (2.1) | 1.7 (2.1) | 0.4 (−1.0 to 1.7) | 0.60 |
| Secondary outcomes | ||||||||
| KOOS subscales‡ | ||||||||
| Physical function | 61.0 (16.0) | 63.0 (14.7) | 71.2 (15.4) | 71.0 (14.3) | −10.2 (14.5) | −8.0 (11.4) | 1.6 (−5.8 to 8.9) | 0.67 |
| Pain | 52.5 (11.3) | 55.1 (12.8) | 63.0 (14.3) | 64.1 (12.1) | −10.5 (14.8) | −9.1 (15.3) | −0.4 (−8.6 to 7.8) | 0.92 |
| Sport and recreation | 24.7 (18.3) | 28.0 (22.9) | 31.1 (24.6) | 39.3 (16.4) | −6.4 (27.1) | −11.4 (25.9) | −7.8 (−20.8 to 5.3) | 0.24 |
| Knee-related quality-of-life | 32.6 (13.0) | 34.1 (14.3) | 37.5 (18.8) | 44.3 (17.3) | −4.9 (18.1) | −10.2 (17.1) | −6.1 (−16.8 to 4.5) | 0.26 |
| Patellofemoral pain and osteoarthritis | 33.2 (16.1) | 33.5 (15.3) | 40.2 (20.7) | 44.1 (15.6) | −6.9 (21.0) | −10.6 (15.0) | −3.9 (−14.4 to 6.6) | 0.47 |
| Quality of life (AQoL-6D)‡ | 0.80 (0.10) | 0.76 (0.10) | 0.81 (0.10) | 0.78 (0.12) | −0.01 (0.13) | −0.02 (0.06) | 0.00 (−0.05 to 0.06) | 0.90 |
| PASE‡ | 186.5 (78.5) | 177.9 (91.8) | 177.0 (84.1) | 202.5 (89.4) | 9.5 (85.7) | −24.6 (51.5) | −32.2 (−73.1 to 8.7) | 0.12 |
*Difference is adjusted for the outcome at baseline and radiographic severity (Kellgren and Lawrence grade).
†For change within groups, positive changes indicate improvement. For difference in change between groups, negative differences favour the motion control shoes.
‡For change within groups, negative changes indicate improvement. For difference in change between groups, positive differences favour the motion control shoes.
AQoL, Assessment of Quality of Life (−0.04 to 1.0; higher scores indicate better quality of life); KOOS, Knee Injury and Osteoarthritis Outcome Score (0 to 100; lower scores indicate worse pain/symptoms/function/quality of life); NRS, Numeric Rating Scale (0–10; higher scores indicate worse pain); PASE, Physical Activity Scale for the Elderly (0 to over 400; higher scores indicate higher physical activity).