KOA (Knee osteoarthritis) is a common joint disease in geriatrics. For managing KOA, exercise therapy is one of the most valuable approaches for non-pharmacological treatment. However, there is a requisition of low exercise adherence to be enhanced.

The study evaluating the effect of the TTM-HEI (transtheoretical model-lead home exercise intervention) program depicted that in the long term, TTM-HEI could improve the patient’s knee function, exercise adherence, and KOA symptoms. In community centers, this program can be applied to enhance exercise adherence and attain excellent practical results.

The two-arm, superiority, assessor-blinded, cluster randomized trial aimed to determine the long-term effect of the TTM-HEI program on exercise adherence, KOA symptoms, and knee function in community-dwelling older adults with KOA.

From 14 community centers in China, community-dwelling older KOA adults were enrolled via print and social media advertisements from April to October 2018. The study recruited 189 older adults (Intervention group: n = 103, Control group: n = 86) and lasted for 48 weeks (Intervention duration: 0– 24 weeks; Follow-up time: 24–48 weeks). A two-stage and 24-week TTM-based exercise program were included in the intervention. The Control group experienced a similar-length exercise program guidance devoid of any exercise adherence interventions.

Exercise adherence of participants to the prescribed home exercise program was the primary outcome measure. It was collected at weeks 4, 12, 24, 36, and 48 after the initiation of the program utilizing an 11-point numerical self-rating scale. KOA symptoms and knee function were the secondary outcomes that were gathered at weeks 0, 24, and 48. Utilizing the WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), estimation of KOA symptoms (joint stiffness and pain intensity) was done.

Using the FTSST (Five-Times-Sit-to-Stand Test) and the TUG (Timed Up and Go Test) at baseline, week 24, and week 48, knee function (lower limb muscle strength and balance) was estimated. The main statistical tests used were the GLM (Latent growth model), independent t-test, and repeated measures ANOVA.

No substantial differences in any outcome measures at baseline were witnessed between the two groups. In the Intervention group, the growth rate of exercise adherence was found to be greater (2.175 units) when compared to the Control group. At week 48, the Intervention program maintained participants’ exercise adherence with 5.56 (SD = 1.00) compared with 3.16 (SD = 1.31) in the Control group as depicted in Table 1 and Figure 1:

Figure 1:  Exercise adherence scores in both groups over 48 weeks 

For KOA patients, the TTM-HEI program demonstrated significant effects on alleviating KOA symptoms and improved knee function.