Factors Affecting Physical Activity of People with Knee Osteoarthritis in Southern Taiwan: A Multiple Logistic Regression Analysis

BACKGROUND: Physical activity (PA) is a basic and initiative conservative management for people with knee osteoarthritis (KOA). This study aimed to explore the potential indicators of PA levels in people with KOA. METHODS: We designed a cross-sectional study where people with KOA were consecutively approached by the Orthopedic Outpatient Department in a hospital in southern Taiwan. People older than 50 years that could communicate and consent to the present study were enrolled. As a dependent variable, the Chinese version of the Physical Activity Scale for the Elderly (PASE-C) was used to assess the participant's PA levels. Considering differences in sex, a PASE-C score cut-off point of 140 for men and 120 for women was used. Participants were then divided into “active” and “inactive” groups. We measured independent variables consisting of the demographic and clinical characteristics, such as comorbidities measured by the Charlson Comorbidity Index (CCI), depression status measured by the Geriatric Depression Scale-5, body mass index, KOA history (<5, 5–<10, and ≥10 years), knee pain (unilateral or bilateral), the severity of symptoms measured by the Western Ontario and McMaster Universities Osteoarthritis Index, and 6-meter preferred walking speed. Multiple logistic regression was performed to identify significant relationships between PA among people with KOA. RESULTS: We analyzed a total of 188 people with KOA (56 men and 132 women) with a mean age of 69.4 ± 7.9 (range: 51 to 90 years). Approximately 72.9% (n = 137) were categorized as “inactive PA,” while 27.1% (n = 51) of participants were categorized as “active PA” (male: 32.1%; female: 25.0%). Multiple logistic regression showed a positive association of 6-meter preferred walking speed with active PA (OR: 7.08; 95% CI:1.14–44.13), whereas advanced age and comorbidity (CCI≥1 vs. CCI<1) were negatively associated with active PA with an OR (95% CI) score of 0.91 (0.86–0.97) and 0.37 (0.15–0.87), respectively. CONCLUSIONS: People with KOA require appropriate lifestyle management to increase PA. Walking speed may be an effective factor for predicting PA among people with KOA. Healthcare providers treating KOA patients should be aware of their PA levels, especially those at risk.