Discussion
knee osteoarthritis
SECONDARY, KNEE OSTEOARTHRITIS
In this RCT we aimed to investigate the efficacy of strength exercise or aerobic exercise compared to usual care on KOOS QoL at 1 year in individuals with symptomatic knee osteoarthritis. Our secondary outcomes included several functional and physiological outcomes at 4 months and 1 year. We did not detect statistically significant between-group differences for knee-related QoL at 1 year, but our results had wide CIs. A recent systematic review evaluating the effects of exercise for patients with knee osteoarthritis [Our results are most likely influenced by the smaller sample size than what we intended to include, but the wide CIs might also reflect that the participants have conducted and responded individually to the interventions. Future studies should investigate more thoroughly who is responding to exercise interventions and probable explanations behind clinically important improvements or differences. Furthermore, the lack of efficacy at 1 year might relate to adherence to the exercises both in the intervention period, but also in the post-intervention period. The interventions might not have been optimal for a heterogenous group of patients with knee osteoarthritis with some having previous injury, some were overweight, and they had different experience with moderate intensity training. The physiotherapists were told to tailor the intervention within the frame of the program, but we have no information on how this was conducted other than information from the training diary. We did not collect data on information the physiotherapists gave to the participants during and at the end of the intervention, but we assessed health care utilization at 6 months, 9 months, and 12 months (physiotherapy consultations presented in Table 