Table 2.

Change in WOMAC pain scores at 6, 12, 18 and 24 months^† and knee related physical function and stiffness at 24 months

Outcome	No of participants	Baseline	Mean difference at 24 months†	95% confidence interval for mean difference	df	F	P	Effect size
Primary
Knee pain at 24 months*:
Exercise	467	7.15	−0.82	−1.3 to −0.3	1 and 779	11.14	0.001	0.25
Non-exercise	316	7.35
Telephone	393	7.10	−0.16	−0.6 to 0.3	1 and 779	0.45	0.50	0.05
Non-telephone	390	7.40
Knee pain at 6 months:
Exercise	467	7.15	−0.61	−1.0 to −0.2	1 and 779	8.64	0.003	0.21
Non-exercise	316	7.35
Knee pain at 12 months:
Exercise	467	7.15	−0.61	−1.0 to −0.2	1 and 779	7.80	0.005	0.20
Non-exercise	316	7.35
Knee pain at 18 months:
Exercise	467	7.15	−0.69	−1.1 to −0.2	1 and 779	9.10	0.003	0.22
Non-exercise	316	7.35
Secondary
Physical function:
Exercise	466	23.15	−2.57	−4.1 to −1.1	1 and 778	11.44	0.001	0.25
Non-exercise	316	22.97
Stiffness:
Exercise	470	3.42	−0.29	−0.5 to −0.1	1 and 782	6.44	0.01	0.18
Non-exercise	316	3.46

^*Interaction of exercise and telephone (P=0.54). 

^†Negative values for mean differences reflect improvements in knee symptoms compared with baseline.