Impact of home exercise program on self-efficacy and quality of life among primary knee osteoarthritis patients: a randomized controlled clinical study Abstract Background: Knee osteoarthritis (KOA) is a common joint disorder in elderly individuals, causing pain, loss of physical functioning, disability, and reduction of life quality. Home exercise programs (HEP) serve as a crucial complement to outpatient rehabilitation therapy, as they save the cost of supervised physical therapy sessions, while also offering a high level of treatment. The aim of this study was to evaluate the effectiveness of the 6-month HEP on pain, quality of life, and self-efficacy in patients with primary KOA and to identify the adherence level to exercises and associations with patients’ characteristics and clinical outcomes. Results: After 6 months of HEP, there were statistically significant differences between groups for self-efficacy (p ≤ 0.001, from 58.29 to 71.5) (p = 0.23, from 55.98 to 57.72), quality of life (p ≤0.001, from 60.1 to 72.2) (p = 0.074, from 60.35 to 60.92), and pain severity (P ≤0.001, from 58.29 to 41.4) (P = 0.88, from 61.2 to 60.9) in favor of exercise group. Conclusions: Home-based exercise program improves pain score, self-efficacy, and quality of life in patients with knee osteoarthritis. Adherence level to the exercise program may have a positive impact on patient improvement. Keywords: Osteoarthritis, Knee, Adherence, Home exercise, Self-efficacy, Quality of life